Texas: Sister Signed Contract With Estate Sale Company. She’s Not The Administrator.

Prior to probate, my sister signed a contract for an estate sale company to clean out my late mother’s home. It hasn’t been going well unfortunately.

Probate hearing has completed now, and I’m the administrator. I want to terminate and hire a new company. I understand the contract would be needed here to get a truly accurate answer, but hypothetically are we able to break a contract when the client (my sister) isn’t even authorized to sell my mom’s belongings to begin with? Seems as though the administrator is the only one who can sign a contract for an estate sale of the property.

Going to gauge my probate attorneys opinion on this as well.