7/2013--Info courtesy of Kimmie925.
Mrs. Rebecca M. BYRD, relict of Maj. Abraham BYRD, born in Shenandoah county, on the 23rd day of November, 1794, at the residence of her son-in-law, Rev. L. S. REED, in Harrisonburg, on the 16th of July, 1870. She was the daughter of Isaac SAMUELS, Esq., dec'd, and the sister of the late Hon. G. B. and Joseph H. SAMUELS, so well known in the Valley of Virginia, and the last of the family. She was, for at least fifty years, a consistent member of the Evangelical Lutheran Church.
From the Rockingham Register, 21 July 1870


10/2012--Info courtesy of Sherry Johnson.
Abraham and Rebecca Samuels Byrd were my great great grandparents.The issue with Rebecca/Rebekah's dates is an on-going problem.

Rebecca's death record from the Bureau of Vital Statistics contributes to the problem. Although it says she died in July of 1870, the death was recorded in sequence in 1869 (all others on both sides of her entry are 1869). I've tried to figure out a reason the recorder would have plugged an 1870 death in between other reported deaths on the 1869 page. I've not seen a copy of the original, but think the 1870 is a typo. Other errors include her father's name [Joseph Samuels was her uncle; father was Isaac Samuels] and her son-in-law was Lemuel, not Samuel, Reed. Her son-in-law, Rev. Lemuel Reed, was the father of the famous Dr. Walter Reed. These additional errors cause me to wonder just how much Rev. Reed knew about his wife's mother's vital information after only 3 years of marriage to Mary Byrd Reed.

Virginia State Library (VSL): Bureau of Vital Statistics, Death Records, Reel 26 Rockingham Co
http://www.rootsweb.ancestry.com/~varockin/deaths1869.htm
Meaning of numbers: Reel 26 Rockingham Co; year; page; number (N denotes no given number but assigned number according to sequential order)
Order of Data per record: Name; Race; Sex; Death date; Death place; Cause of death; Age at death; Parents; Birth place; Occupation; Marital status; Person giving information; Relationship to deceased (NR denotes "not recorded")
R26-1869-3-3 Rebecca Byrd; white; female; July 1870 [sic]; Harrisonburg; NR; 76-x-x; Joseph & ____ Samuels; Shenandoah Co; NR; Abraham Byrd, decd; Samuel S. Reed; son-in-law [NOTE: the 'sic' is part of the transcribed record, not an addition by me. sj]

Here's how I've used all these dates to arrive at my own conclusions.
I see you've apparently looked at the inscription personally and interpreted the date of birth as July 4 and the date of death as Feb. 11--hope I'm interpreting your 7/4 and 2/11 correctly. Is it possible that these dates are reversed, as the July date would correspondence with the family information and the curious death record. If that is the case, I'd figure 4 July 1870 as the date of death.
The instructions to census enumerators in 1850 with regard to age were: Under heading 4, entitled ‘‘Age,'' insert in figures what was the specific age of each person at his or her last birthday previous to the 1st of June... Rebecca's age at the time of the census taken on 25 Sept. 1850 was shown as 54 years, with the enumerator correctly reporting her age as of June 1st, even though she would have been 55 years of age on July 4, 1850, before he reached the Byrd home for enumeration. This would suggest that her likely birth date 4 July 1795. Unfortunately, I've not found the Byrd family anywhere on the 1860 census to confirm this age. I also have to tell you that Abraham's age was reported as 58 (off by 2 years) on the 1850 census and we know his exact birth date from a family bible that is still in existence, but Rebecca may have not have consulted that bible if she was the person responding to the enumerator's questions.
Age at death according to the HRHS site was 75y 1m 23d; using the above birth date would make the date of death 1871. Given the information on her death record, this later date seems unlikely. Also, since she does not appear on the 1870 census, it is likely that she had died earlier. I've looked for her with all of her surviving children and she was not living with any of them.
You usually assume when you see the y/m/d that someone knew the exact birth to do the math from the day of death (more likely to be known first hand by the reporter of the death), but in this case, I think the y/m/d age at death was probably not accurate and that Rev. Reed who had been married to Rebecca Byrd's daughter only three years probably was going on family accounts without checking records when he reported her death.
The following account is included in John W. Wayland's Historic Harrisonburg: ""Mary Catherine Byrd daughter of Abraham and Rebecca Samuels Byrd was widow of Robert M. Kyle when she married my father [writer was Mrs. Douglass T. Elam, a half sister to Dr. Walter Reed], Rev. L. S. Reed on Dec. 11, 1866. At that time he was in charge of the Charlottesville District and moved to Harrisonburg for one year in 1870 to be near my aged grandmother, Mrs. Rebecca Samuels Byrd ... On July 24, 1928, I [Wayland] received from Mrs. Elam another letter...When my mother married my father in 1866 she at once moved to Charlottesville with him, where they lived until the fall of 1869, when he moved to Harrisonburg so she could be with her mother...Grandmother died in July of 1870, and my father returned to the Virginia Conference, my mother spending the winters with him.""

The writer of this letter was only three years old at the time the Reed family was shown on the census living in Harrisonburg in 1870, so she could not report from personal knowledge that her parents moved back there in 1870. I'm sorry that I cannot give you a clear reply regarding Rebecca's birth and death dates, but with conflicting information, I simply don't have the answers right now. I think now might be a good time for me to write to the county for her probate records, which may at least give us the date of her death. I'll let you know if I am able to acquire these records and they give any clarification.
The following account is included in John W. Wayland's Historic Harrisonburg: ""Mary Catherine Byrd daughter of Abraham and Rebecca Samuels Byrd was widow of Robert M. Kyle when she married my father [writer was Mrs. Douglass T. Elam, a half sister to Dr. Walter Reed], Rev. L. S. Reed on Dec. 11, 1866. At that time he was in charge of the Charlottesville District and moved to Harrisonburg for one year in 1870 to be near my aged grandmother, Mrs. Rebecca Samuels Byrd ... On July 24, 1928, I [Wayland] received from Mrs. Elam another letter...When my mother married my father in 1866 she at once moved to Charlottesville with him, where they lived until the fall of 1869, when he moved to Harrisonburg so she could be with her mother...Grandmother died in July of 1870, and my father returned to the Virginia Conference, my mother spending the winters with him.""

The writer of this letter was only three years old at the time the Reed family was shown on the census living in Harrisonburg in 1870, so she could not report from personal knowledge that her parents moved back there in 1870. I'm sorry that I cannot give you a clear reply regarding Rebecca's birth and death dates, but with conflicting information, I simply don't have the answers right now.
Re: Maggie This is indeed the nickname for Margaret Elizabeth Byrd, although the 1850 census gives her name as Elizabeth M.
Death Record: Byrd, Margaret white female 14 June 1862 cause inflamation of bowels aged 32 yrs Father: A___, Mother: Rebecca birthplace: Rockingham [Source: Rockingham Co., Va. Deaths 1862-77]

004 009 Byrd, Maggie E. 7 Feb 1829 14 Jun 1862 Aged 33y 4m 7d

Abraham Byrd's birth date is from an old bible still in the family (one of two) that records birth dates all the way back to 1754. His death date was:

"Byrd, Abraham white male 14 May 1862 disease of heart 72 yrs.___ ___ Father: Andrew Mother: Ann birth place: Rockingham."

Just to prove nothing is ever cut and dried ...
Spencer, Carrie Esther Samuels, Civil War Marriage in Virginia: Reminiscences and Letters, Boyce, Va.: Carr Publishing Company, c1956, p. 137.
"[Letter from Green B. Samuels III to his wife Kathleen Boone Samuels. Written at Harrisonburg, May 16th, 1862]
"My Dear Wife...My Uncle Byrd died yesterday and is to be buried tomorrow..."