Interesting that you posted this today. I have been looking also but not for one as large. I would suggest, personally, that you consider a Boston Whaler. For the size and price you want to pay you can likely get a nice one but doubt there will be any cabin for a potty....as was previously posted, tell her to pee in the water
They are the Porsche of boats and have great resale. Be sure to get a marine survey done like on any boat. CraigsList is a good place to get ideas of what's out there but CL folks can be really flakey. I just lost two deals when sellers decided to keep the boat at literally the last minute.
Most Whaler owners tend to take really good care of their boats.
You can see many sizes and models at the BW web site:
www.bostonwhaler.com but buying new is like buying a car new...lose a lot the first year.
Good luck with the search and let us know what you get and/or your top picks..