If a home was willed to my brother, sister and I and mybrother sold his share without my consent, what is my recourse?

Was there some sort of restriction on the transferability of his share in the Will? If not, a co-owner can sell their share of jointly held real estate. Basically, the only limitation on conveying such property is if the original deed contained such wording as "with rights of survivorship". In that case the property could be sold but not Willed to another. However, that is not your case here since your brother is still alive. Therefore, while somewhat sneaky, the transfers back and forth and the ultimate sale were perfectly legal.

Note: Only your brother's share could be transferred without your consent; not the entire property.

I am so sorry for your loss and for the situation that has resulted.  I need to dissect the matter and go over it step by step in order to help guide you here.  You are ultimately going to need anattorney in the Florida area to speak with and help you here but you need to understand what you need to discuss with the attorney.  First, as I understand the way you have phrased the question your Mother gave the house to you equally as per her Will.  So the Will was probated and the deed transferred from her name to the three of you via Executor's Deed?  And it was properly filed?  Then your brother quit claimed his portion to you and your sister.  Was that filed?  And then your sister quit claimed her portion back to him but you did not (and no one had a Power of Attorney to do so either) right?  And that was filed?  And then he sold the property.  Your sister deeding back the proeprty does not matter as long as your name was still on the deed.  Then the transfer was fraudulent in some way.  Where it all wen wrong you need to figure out and you need to sue your brother for a false conveyance.  Please get help.  Good luck.