Above is a link for Find a Grave memorial for Margaret Healy; Daniel is also memorialized on the site. Doesn't give a date of death for Margaret. Since you know about her burial, maybe you know her death date? If you do, then a "look up" can be done in the record of deaths on microfilm at the Minnesota Historical Society (I belive deaths that early are not online at mnhs.org). Her death record might contain her parents' names. St. Peters Catholic Church in Mendota might also have a record of her birthplace and/or parents.