People who wind up with other people animals do have protection under the law for compensation. I may be called a Mechanic's Lien, in Ontario it's the Innkeeper's Act. Check with the state/provincial dept of agriculture, country extension agent. The rules are fairly easy to obtain. One these animals enter your property you may have an automatic lien on them. In Ontario one has to publish a notice of debt, namng the person, the amount of debt and the horse's as she called them. State a time limit and name the date. Also state if payment isn't received by that date the horses will be sold at the first public auction. Now, in Ontario, you are entitled to add reasonable fees. Should you retrieve all your board monies and reasonable fees, any remaining must be turned over to the owner. If you wish to keep these horses, get it in writing of the seizure from the sheriff's department. Should the owner show up you have legal claim but don't tell her that. Write down all the expenses and have them handy and demand immediately payment. I promise you she will vanish.