Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How much did you receive
What do you know about this person who has come forward - has she produced a birth certificate?
What paperwork did you sign when you received the money?
Have they said if she has produced evidence of her identity?
The simple fact is that no they cannot release details without your agreement - they can simply say that they paid the money to her "father's" brother
However if she traces you herself and provides evidence that she is his daughter then yes I am afraid you will have to repay her the money - even if it has to be in monthly installments
Please ask if you need further details