I have dealt with pet urine several times, some cases have been severe.  

Certainly you need to be cautious, however I love the smell of cat urine and some termite damage.

Maybe have her read "Turnkey Dad, Cat Urine Dad"Turnkey Dad makes no money off the purchase, pays a premium for turn key, makes an 8% RIO, and develops few additional skills and experience.Cat Urine Dad buys a stinker, builds 40% equity by doing repairs, makes 15% ROI, develops contractor relationship and rehab skills that carry over to future projects. 

here is a pic of the hardwood flooring after a large dog used it as a urinal for about a year.

Of all the problems you can have with pet urine smell, a saturated wood sub-floor is by far the most difficult and expensive to fix.If the urine is from a cat, it's usually only on the floor but if it's from a dog, you might have it on the walls and baseboard as well.

No more carpet cleaning bills or urine seeping into the carpet pad and floor board.

This house was completely full with clutter, cat urine, you name it.  2 people in one week asked me if I had a single family house that they could buy at wholesale from me, so I threw a number at them that made it worth my while for me not to close on my own and do the build out.  

Their deposit did transfer with the sale but I fear the urine damage might surpass the cost to refinish.

I'm talking about stolen appliances, holes in the drywall, broken windows, drug paraphernalia, and even sometimes urine and feces.

Lesley:If the problem is not too severe ... ie. the urine is not completely absorbed into the subfloor and/or walls ... there are concentrated enzyme products you can order on-line (the name of the one we used escapes me at the moment).