Hi

If someone gave birth in a family illegitimately, and a family member took the child on, say a grandmother, or sister, is it possible they could have gone to register the child and put their name down on the birth certificate, instead of the biological Mothers?

There is an ancestor in my family tree who was born in the 1873, and I've heard rumors her Mother wasn't her mother, and the person who she thought was her Mother was an aunt. The birth certificate doesn't show this though. So I'm a bit puzzled.