Legal Question in Real Estate Law in California

Mom can only sell that portion of the property owned by your Father, unless the other siblings or their heirs participate in the sale. What that portion is depends upon how the property was transferred to your father and his siblings. If title was held as joint tenants, after the death of "Dad's brother," the property would belong to Dad and "dad's sister." After the death of Dad, Sister would be the sole owner of the property. If, however, title was held as tenants in common, the property would pass to whomever the siblings designated and, absent any designation (as in a will or trust), would pass to the sibling's heirs by intestate succession. In this case Mom could sell "Dad's" interest in the property without doing anything (assuming that she is the acting trustee of the trust and that the trust instrument allowed the trustee to sell property of the trust) because some portion of the property is owned by the trust.

Two caveats: (1) Your Mother cannot sell the entire property without the consent of the other owners; and (2) although it is not impossible to sell fractional interests in real property, it rarely happens because there really is no market for fractional interests in real property.

Finally, if Mom wants to "get rid" of the property, she can always file a lawsuit against the remaining owners for partition. In a partition action, the court determines each owner's interest in the property and, generally, orders the sale of the property, then divides the net proceeds of the sale between the owners in proportion to their respective interests.

I would need to review the deeds and trust documents to render a reliable opinion. Contact me directly.