Legal Question in Wills and Trusts in California

You don't provide enough information to give any real answer. Is your mother still alive? If so, why is there a trustee? If she has passed away, who is the beneficiary of the trust? If she is still alive, is she mentally competent? If not, are you talking about a conservator rather than a trustee? Ultimately the answer is to drag them into court to account for their conduct, but who has standing and under what grounds to object to the conduct depends on all the factors I have asked about, . . . just for starters.