It is difficult to respond to your question without review the terms of the trust. I suggest that you consult with a probate and trust lawyer.
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She cannot evict you if you defend the matter correctly. Moreover, unless the trust authorizes your occupancy, the probate court can order you out. Your action is self-dealing and you could be held financially liable and potentially subject to double damages. You can also be removed as trustee and held liable for your sister's attorneys fees. I wouldnt push it if I were you. Consult a local trust attorney ASAP
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