I would tell her she has entered into an legal agreement & if she pulls out now that is her choice but she will not get her deposit back.
Tell her you had the work done that she requested & you will be contacting TM if she does not complete the trade & you will be demanding your TM fees back & you will be telling them that she refused to complete the trade...I would tell her she is a time waster..
I would also tell her that if her friend is a good lawyer he will advise her that she has broken the contract & that she is breaking the law (put it all back on her).
Worst comes to worst tell her you will go to "fair go" as you have nothing to lose & she is the one in the wrong.
Good luck...I hate people like her, brings out the fight in me