Meet their pets and children.

Show them how you handle cancellations, obnoxious customers, trashed rentals, unauthorized guests and pets, etc.

I've got pet pee, water leak stains, and misc. crap on the carpet.

You can try and use this to remove ithttps://www.walmart.com/ip/Urine-Gone-Pet-People-Stain-Odor-Eliminator-24-Fl-Oz/24706407

Do they have kids, pets, etc?? 

It's a pain to move off a website, especially if it has all your leads, CRM and marketing systems attached so they'll likely be a client for life.Offer eye-catching upsells to guests like concierge services, butler, car service, pet sitting, valet and parking. 

Adding her to the current lease and charging for the additional pet rent?

I paid it, but i was pissed as most of the dogs played out back off leash. a couple months later i warned a woman of the leash law, and said you are probably safe as the person that complained was only targeting me. 2 days later one of my neighbors marched across the street saying (my wife said you were charged the HOA and fined for pet fee.

We don't charge anything after the 25% and the entire pet fee would go to the owner unless there's extra cleaning. 

Year of update of the systems (roof, plumbing, electric, heat)4. any pets, pools, tranpolines, or business use at any locationThey will usually need more specifics but this is a good start.