Legal Question in Real Estate Law in California

You have not indicated whether the purchase by your sister was with the consent of the lender. There may have been tax implications when your sister bought the house. Were these reported and considered? More importantly, most mortgages in California have a due on sale clause requiring lender consent to avoid acceleration of the loan. Read your loan documents. You may have violated the loan documents if there was not a consent when it went to your sister ( unless she took out her own mortgage), and may do so again if you are not obtaining new financing. You may have income tax consequences to the sale as may your sister. You will have a property tax reassessment for a sale between siblings. You will have to record a deed and will likely have a documentary transfer tax to pay. It is likely worth your while to consider consulting counsel or a knowledgable real estate professionsl to do this,

This is not something I would suggest doing without the assistance of an attorney to advise you and a thorough review of all of the paperwork involved. There is a line of authority in California that acquisition by you of the property will reinstate the original deed of trust.