Legal Question in Wills and Trusts in California

I do not understand your third line from the bottom.

If the original trust document stated that you were to be a co-trustee and had no provision to remove you, then you still are co-trustee and can sue your step-sister for looting the Trust assets. If your step-mother had the power to change trustees and did so before she suffered from mental problems, then the step-sister could be in charge, but the trustee merely operates the trust and is not the beneficary of the assets unless the trust so states. You do not clearly state what the situation was.

You can go to the step-sister and try to reason with her, but it is doubtful you could get her to do aomething different. Before you do that you should read parts of some books on Trusts [Nolo Press has some good books out] so you are aware what to look for and what arguments you can make. Perhaps yuo xcan find some attorney who wil take the matter on a contigent fee.

How much money was in your father and step-mother's estate? Has step-sister spent most of it already? These are the questions you need to answer for an attorney to decide whether to take on a case with no money up front.

Do you have a copy of the document that purported to remove you as trustee?

Most likely you will either have to forget about this or file an action against the step-sister. Once someone goes to the trouble to remove a co-trustee, they rarely cooperate. In my experience, I have never seen such a person cooperate, although I realize it is still possible.