How do I let her know I am uncomfortable?

My grandmother keeps putting money in my account. She doesnt have money just lying around, and I always feel horrible when she gives me large amounts...how do I let her know in a nice way that I am uncomfortable and that she really doesnt need to do this. I am a college student as well.

the reason why she is doing this is because my dad owes me alot of money which he isnt paying me and he has a temper...he is living with her and I was going to ask him for the money...I let her know and she said that she would do it herself...and idk what to say to that...what can I do?