I believe your Bridget Mulhall was born Dec, 1839 in Ireland. Immigrated in 1860. Lived/worked w/ the Catholic church in Grand Junction.
The above link is a free site and you can locate her there. There was no John/Jack Mulhall in Grand Junction between 1880 and 1940 that I could find. There is no record of and marriage of Bridget Mulhall in CO between 1859 and 1939.No Mulhall marriage in Mesa County either No record of any O'Boyle marriages in Mesa County either during that time frame. I get the "feeling" that while not a nun, she worked and served w/ them. She was 80 yrs in 1920 and recorded w/ them. You might contact the Catholic Church there and see what records they might have. Theirs are usually pretty good. Good Hunting