Income Tax on Money given by Mother to Daughter

Hi,

My wife had taken a house loan of 15L before marriage for her parent's house. Now that she is married to me she is continuing to pay the EMI. Now her parents want to give her the lump sum amount of 12L for the loan. She doesn't want to repay the loan with this money, but she wants to invest for our house. My question is in what way she should ask for transfer of money from her parent's account so that it won't come in income tax bracket.

Please advice as it's urgent
Thanks