Legal Question in Credit and Debt Law in California

No, but unless you document things properly, in the event of a future divorce you will not be able to claim reimbursement for paying her separate property debt.

Just because the debt is solely in your wife's name does not make it separate property debt; was the purpose of the debt for the benefit of the community; should or could it be classified as community debt even though in her name; and is not the joint account actually community funds?

If you are trying to segregate funds and debts, you may want to have 3 accounts. (His-hers-joint)

especially if either of you make family support payments; you will want to keep funds separate.

The answer to your question is that the creditor could argue that you assumed the debt if they continued to issue credit based on your joint or community payment....but then they could argue that it is actually community debt because you both benefited and they relied on the continued payment.(weak) but they could argue that you made them do it, too.