Partition Action Response When Claims Are False?

I am co-owner of an inherited house in Florida. I have spent the last 2 years getting it ready for sale and meeting with realtors. The other co-owner has told me she would reimburse me for all the expenses I've paid since my father's death. And we both desperately want to get out of the house and sell is ASAP. I had completely moved-out and was living in another state waiting to get the listing agreement to sign - when out of the blue with no warning the other co-owner filed a partition action in court. This is insane as there is no reason for it and will only delay everything and add tens of thousands in attorneys fees. I haven't been able to get an explanation or clear answer and don't understand what is going on. Attorneys I contacted all want between $5k-$15k to help me- which would all be a total waste, given that I just want to sell the house. The worst part is that the claims in her petition are all not just false - but the opposite of reality. She is claiming that I refuse to sell the house - which is what I've been dreaming of and working for for 2 years. I don't know what to do.