Legal Question in Wills and Trusts in California

There are several different types of documents popularly called "living trusts", so to give a correct answer to your question an attorney would have to review the actual documents to be able to comment on what the situation is. If all the property was transferred to your trust and title to all the property was placed in the trust, then those assets are distributed according to the terms of the trust. None of those assets are part of your mother's estate. Any assets not properly placed in the Trust are part of the estate and there is no statute of limitations as to probating the estate [as the assets would remain in the estate until probate occurs].

If you want, I could review those documents. You should have an attorney review the Trust documents and then write to your siblings as to what the legal situation is and also explain why your mother apparently set things up as she did.

I don't understand when you say you set up two trust and yours had all the assets in it. Did you set up one trust with Mom's and your assets as a joint trust? If so, the siblings may have an expectation of getting part of Mom's estate. If you took Mom's assets under the POA, it was to provide for her care during her life; it did not transfer the assets or right to them to you for doing so. As state above, though, it is hard to say without actually seeing the documents.