Bismihi ta'ala
The simple answer is no, the wife has absolutely no financial obligations towards her husband, her in-laws, or anybody else.
Anything she gives, she gives out of her good will and good akhlaq. She has the option of being generous and contributing, if she is capable of doing so, and willing, and she has the option of not, as that is completely up to her.
The husband or his family have no right forcing her or persuading her to contribute, and she needs to be careful to know her rights. If she is contributing to the mortgage, then she has an option of being a part of the legal ownership of the property, and so on...
With prayers for your success.
She must be careful that she is not being mistreated or manipulated in