I am a paralegal so until we hear back from the attorney Wylie's Mom contacted, I'll add my two cents. Obviously I have never seen the contract and don't know all the facts, so this is only my opinion.
If the OP intends to bring a legal action against Emma's breeder, not only shouldn't she spay Emma, but she needs to keep possession of Emma and not sell or place her with a third party.
The court will have to have a remedy to this dispute in order to decide it and most likely will consider returning Emma to her breeder for a full refund as one option. If the court does not have a remedy to grant relief, it will just dismiss the case.
Another thing to consider is that a rescue group may not take Emma if there is a legal action pending as they might not be able to place her until the court decides the case. Can you imagine the nightmare if the court decided that Emma had to be returned to her breeder and she was already placed with a family?
Sadly for Emma, if the court is asked to decide her fate, she will have to remain in limbo until it does.