Hi
The other thing to do is to search the 1891 census on Ancestry, just putting in her first name, no surname, year of birth (she was apparently only 15 when she married according to her age on the 1881 census and place of birth.
I did a quick search, putting in a year of birth as 1862 +/- 5 years. If you then exclude all the ones who have children living with them, who would have been born too early for Ellen, or whilst she was with her husband, you will probably end up with quite a list, but you could pick out the ones you think most positive, if supposedly married check on FreeBMD for a marriage from about 1875 to 1891, and if there is no apparent marriage follow them up on the 1901 census.
For instance, the first interesting one I found was called Ellen Balfe, born St. Helens about 1860, boarding with her husband Thomas Balfe, who was born in Dublin, Ireland. No children shown. I then went to FreeBMD to see if there was a marriage to rule out your Ellen and there was in 1886, Thomas Balfe and Ellen Elliott.
It is a time consuming exercise, but you may turn up something like I did with my 2 x g.aunt who was in a different town living with another man and posing as his wife and using his name, even though her own husband was alive and living with his wife's sister's family. My search was made easier by another Rootschatter who found the marriage of the daughter of my 2 x g.aunt and uncle and then found her on the census with this "other" family.
Lizzie