Born in Lowell one year after the incorporation of the city, her baptismal date (per church record) was 6 April 1837 at the Saint Patrick Roman Catholic Church, in which was opened for service to the Irish community a year prior. It is believed that her father, Daniel was on a digging detail to create the canal(s) for the purpose of powering the textile mills, putting Lowell on the map to kickstart the industrial revolution for America.

Her family had moved to Saxonville, then later to Roxbury, Massachusetts, probably following where the father could find available work. In seeking better opportunity, they decided to go west in 1851, first to Cedarburg, Wisconsin. The Wisconsin territory had just obtained statehood on 28 May 1848 and the town was still then part of Washington County. At that time roads were widened, improved and made more passable out of the original Indian trails, the Cedarburg road were then "planked". The family took survey of the land still forested and covered with marshes. After a year, the family found land, 80 acres at cost of $1.25/acre in Section 34 in the midst of Irish settlement at the Town of Saukville to carve out as a farm.

By 1853, the year when Ozaukee County was created out of the Washington county with Port Washington as the seat. At that time, Mary moved away from her family to Juneautown. This was one of three early villages, the other two being Kilbourntown and Walker's Point. All three villages were merged to create the new city of Milwaukie the following year in 1854.

She enrolled as a candidate/student at the tender age of 16 at the Motherhouse of the School Sisters of Notre Dame on the corner of Jefferson and Ogden Streets. The record indicated how she used Isabella as her first name. And in making the vows, she chose the religious name as Sister Mary Hilarice/Hilaria.

By 1856, she professed in first vows and her first assignment was teaching at St. Mary's Assumption in New Orleans, Louisiana. One could imagine the amount of anxiety she may encountered being deep in an "enemy territory" when Louisiana seceded on 26 January 1861 to join the newly formed Confederacy, and that the three of her four brothers volunteered as foot soldiers for the cause of the Union. By 1865, after nine years in New Orleans when possibly after Gen. Lee's surrender at Appomattox and the South by large being laid in economic ruin, it was time to move around so her next teaching assignment was in Baltimore, Maryland at the Institute of Notre Dame.

By 1867, she returned to Milwaukee for the final vows and then took up teaching at St. Mary's Institute facing the corner of Milwaukee and Knapp Streets, adjacent to the Motherhouse.

In 1872, she fell ill and took a year of recuperation at the Motherhouse and still needed an additional year of recovery at the Visitation in Elm Grove, Wisc., another SSND facility.

In 1878, she recovered enough to return to New Orleans as a helper at St. Mary's Assumption. However after one year later, she decided to leave her religious community.

In her return to Milwaukee, she tried to offer nursing services as indicated in the 1883 Milwaukee city directory listing 490 Astor as her place of residence. The work may come too slow for her when her sister Ann Teresa was teaching in Chicago so she jumped the opportunity to live with her and offered dressmaking as seen in the 1885 Lake city directory.

Her mother, Ann passed away in January 1889. Thus a quit-claim deed was made in November, 1890 where Mary collected the sum of USD$150 from brother Daniel Eugene, acting as executor for the sale transaction of the 80-acre family farm in Saukville. It showed she was still living in Chicago at that time of recording. Then the 1892 Lake city directory listed her address on 719 Dempster Street in Evanston, Ill. where she worked as a servant.

By 1895, a couple of clippings printed in the Milwaukee Sentinel only said this much: she was living with baby brother Edward McGinley on 159 Albion Street downtown Milwaukee. It can be safely said how she did not stay in one place long enough to allow grass grow between her feet. The last one was on June 5, when Mary went out visiting an acquittance at 200 Queen Anne Place and was suddenly taken ill and then dropped dead shortly after noon. The cause was heart disease. A burial permit was then applied.

In an amazingly total absence from any U.S. census rolls, her file on religious vocation from the national archives of SSND and the cited sources above has helped Mark Hansen write up this biosketch.