putty in hands
putty in (one's) hands
Easy to control or bend to one's wishes. (Putty is a very malleable material.) Oh, come on, Julia is putty in our hands—we can definitely get her to help us with this prank.
*putty in someone's hands
Fig. [of someone] easily influenced by someone else; excessively willing to do what someone else wishes. (Putty is soft and malleable. *Typically: be ~; seem like ~.) Bob's wife is putty in his hands. She never thinks for herself. Jane is putty in her mother's hands. She always does exactly what her mother says.