Hi again,
I can't see Ellen either in 1891 or 1901 nor a death/marriage

Cheetham Hill is a district of Manchester. I think the family were in Crumpsall in 1881.
You can see they are next to each other on the map.
Rawtenstall where the Margaret Ellen was in 1901 is quite some distance away in Lancashire and the Morris girls were living in Bradford, Manchester in 1891 which, if you look at the map, is round about where Ancoats is (on the map just near the large 'Manchester'.
Just found out that this link only links you to Google maps- you will have to enter Cheetham Hill.
http://maps.google.co.uk/maps?hl=en&tab=wlThe marriage on the other hand took place in Whalley Range which is the other side of Manchester (south on the map).
Hope all this makes sense

It may be worth trying the marriage certificate.