Lis Pending filed on my Mother's property without a pending lawsuit or foreclosure

My Mother recently inherited a property from her brother who died of cancer. He had a woman move in with him to help take care of his home while he was sick. Within 2 weeks of her living there, my Uncle went into the hospital, never rebounded and died 8 weeks later.Against my advice, my Mother gave the woman 1 month from my Uncle's death to find a new place to live. My Mother had a buyer for the property if it was vacant in that one month. The woman seemed very nice and appreciative of have a place to live rent free for 3 months and claimed she would be moving out by deadline. On the final day of her free rent, the woman told my mother that not only was she not moving out but the property was owed to her for unpaid services as a caregiver and improvements she made to the property. She then filed a construction lien even though she had no contract or permission to do home improvements and in fact had only mowed the lawn. My mother lost the buyer, had to pay 3 mortgage payments, and spent alot of money to evict this woman. The filing fee for eviction in Florida was $80 dollars the week before and went up to $270 3 days before my Mother filed. She also had to pay the Sheriff Dept. many misc. filing fees including the fees to get the construction lien proven false. The Judge ordered a hearing for some unknown reason since this woman is a crazy, lying quack, which my mother eventually won but it was 2 months and 19 days from filing for eviction untill this woman was forced to leave which was 2 days ago. My Mother now has a new buyer but the day before the woman had to go, she filed a Lis Pending. My Mother is about to go crazy since all she knows is this is something that will stop her from selling the property and it certainly seems that the law is all on the side of liars and users since both of the papers she filed cost her $10 each while it cost my Mother thousands of dollars to fight her bogus claims. Any advice on what to do now. Just tonight I found out what a lis pending is and there is no pending lawsuit now. How do we get rid of this from property records and sell the property. My Mother lives on a small pension and social security and this has taken all her savings. She can't even pay Sept mortgage and is now afraid of losing the property. How can the law be so against the good person and let a freeloader get away with so much?????