Legal Question in Real Estate Law in California

Inform her that if she leaves, she will be in breach of her lease, and that you will try to mitigate your damages by finding a replacement tenant, but that she will be liable to you for any loss of rent you incur, as well as the reasonable cost to advertise the vacancy and find a new tenant.

I suggest that you then get two self-help paperback law books. One should be on landlord-tenant rights and relations, how to be a landlord in California, or the like. The other should be on how to use small claims court, such as the Nolo Press book "Everybody's Guide to Small Claims Court in California."

If there is a breach, you can deduct your losses after mitigation efforts from the deposit, and if the deposit is insufficient, you can sue in small claims.