I signed a contract with someone to buy a home in California. But I find out that she's trying to milk me for money. So I tell her that I don't need her services anymore. And she replied to my email by saying "ok ill throw all your paperwork away" Will I get sued if I signed with someone else and buy a home? Or was that email binding?

I believe that could be considered to have released you from your contract.

Did her email copy your email, so it specified what paper work was being thrown away.

I would not rely on the email alone.

How can you prove that it was her that sent you the email?

If push came to shove, couldn't she deny sending it, and claim that "an employee" sent it by mistake, or that you had someone send it, pretending to be her?

Try to obtain something written and signed, just to protect yourself should things go sour.

Her exact words were "ill thrash your personal information away" and she emailed me later asking why I didn't go with her for her own personal development. Personal information, would that also say she's trashing the agreement or just personal info like w2 etc etc