You can, technicallly, but please consider it carefully.
Its the one place at WDW that is geared for adults, essentially a section of night clubs fairly close to DTD. In the past you paid admission to PI and this gave you access to all the clubs, now you pay only if you choose to go into the clubs. They offer several types of clubs, disco dancing, country western dancing, comedy and such - I can't recall exactly how many. My experience in the Adventurers Club and Comedy Warehouse was wonderful but some of the language and references made me blush!
In addition the outside vendors sell alcohol even such things as jello shots and some really cool looking drinks that had steam and smoke. They do have outside entertainment on a stage or two and you most likely will see some "adut" behavior and some obviously drunk people outside as well as in the clubs.
My rule of thumb is if you wouldn't bring your 5yo out for a night of dancing, clubbing and bars at home you probably won't be comfortable bringing her to PI.
If you really want to see PI, consider checking into the kids clubs, my girls love them. DH and I take one night for ourselves if the vacation is long enough and the girls find it a treat to have a night for themselves. They ask every trip if they can "have a kids night" and visit a kids club.
If not, maybe a trip to DTD in early evening for dinner and shopping. This wasy you can take a peek into PI before it gets too rowdy so you can decide if it's something your ok with or want to do enough to schedule for a future trip or do the kids club.
Have a great trip.
TJ