Mary and Ellen arrived aboard the SS Germanic, sailing from Queenstown on 28 March 1901, arriving at New York on (date not filled in).
They give their destination as their cousin, Mary Deane, 218 East 30th Street, New York. They were last of Belumllett(?), Ireland. They seemed to be travelling with a few others from the same place. It might be Belmullet, Ireland for which I get hits on Google.
I think I found Mary still living in New Rochelle in the 1910 New York Census, on her own, working as a dressmaker. Indicates she arrived in 1902 (close enough), aged 27, and single. This Mary Healy is still in New Rochelle at the time of the 1920 census. In this case, she is listed as being born about 1880 (closer), and she has another sister, Margaret F., aged 29, living with her (immigrated 1909). There is another boarder, Jean Rodden, also living in the household. Mary's occupation is a hair dresser, while Margaret is a registered nurse.
In the 1930 census, she is born 1886 (aged 44), and living with her is an aunt, Mary McQuade, aged 76, widow, having arrived in 1870. Mary is working as a cleaner in a public school.
In the 1940 census, she is still making herself 10 years younger, but is living on her own, still in New Rochelle, working as a domestic.
The 1915 New York State Census has Mary, Ellen and Margaret all living together in New Rochelle. There is also a Frank Doody, listed as a brother-in-law in the household, aged 37, born England, a bookkeeper.
I find Frank Doody in the 1910 census married to an Alice E. Doody, aged 28, born in Ireland, living in Waterbury, Connecticut. Perhaps Alice is another sister?