Hi
I think if her father was in the army then she may very well have moved quite a lot with him and the regiment. If her parents died while she was young, neither child is with one or both on the 1881 census, then she may very well have been confused about where she was born. On the 1881 census she is a young servant in the household, so she isn't the one returning the household information. If she had an Irish accent or indeed any accent there may have been assumption on the part of the head of household as to her origins.
There doesn't seem to be a census return for Charles Cooke post 1861 in this country which may be an indicator he did die before the 1881 census. Obtaining certificates would confirm whether he was or wasn't the father of the two children and who the mother was to determine hopefully where they married.
Regards
Valda
