Assuming that you are not a party in this case. So, first of all, why did you give her money? Legally, if you are not a party, she is not related to you either. Now, in this case, if you go and give money to a neighbor and do not document it as a loan, he is not legally liable to pay back your “Loan”.
Else if she was your daughter – in – law when you gave her money (which is not loan unless documented), it becomes her streedhan legally and so you cannot claim it back. I know this would sound really bad but this is legal reality and all of us are facing the pain of the same.