I am so sorry for your loss and for the situation that has arisen since your father has passed.  It is hard to say what the trust means with out reading it in its entirety but understand that fighting over it will only cause you grief and legal bills. So maybe try and come to reasonable middle ground. It sounds like you both have the right to live there but also the responsibility to maintain it - or the estate does.  So how about you pay for the electric, gas, water, etc., and any maintenance up to $100 say in exchange for living there until you can secure a mortgage. That may appease your sister.  Good luck.