Once you take title they can come after you regardless of your roll in the contamination.

(See WHY MOLDS KILL below)I will be the first to admit that baled hay and grass contaminated with Stachybotrys killed hundreds of horses and cattle in Europe and parts of Russia, many, many years ago.  

Second, if meth was involved or suspected, you want to make sure your house is not contaminated.

What I don't know is whether it was like this every summer before and the tenants just didnt care...The poor bastards at the HVAC company have cleaned the coils multiple times, checked the pressures, and at their last visit emptied the entire unit of coolant, put in a new pump just in case, and then weighed the coolant back in to make sure there were no contaminants.

Low and behold soil contamination was found.

That later emanated through everything when I moved in and contaminated all of my clothes/belongings so I was slightly frustrated of not being told that.

A house was recently withdrawn from the market because a potential buyer had a meth inspection that came back with high levels of meth contamination - indicative of a lab rather than just smoking it inside. 

First - remove the source and anything contaminated by the animals.

Since LL was one of the biggest sinners when it came to Ortho Pthalate contamination in their LVT I'd make sure that the box states it's ortho pthalate free otherwise return it.

Wear masks, gloves, booties...don't give her any opportunity to claim you contaminated her home.May the force be with you...