Well to put it simply -- don't leave her alone to wander the house unsupervised. When she is out of the crate, keep her on a leash and keep her with you so you can supervise her. When you can't, then crate her. THE SECOND she starts acting like she needs to pee, bring her outside.

Have you brought her to the vet for a checkup to rule out any possible health problems that may be causing this?? Perhaps a bladder infection or something of the sort?

It's common among females, and dogs in general, to pee when they get very excited, so you're doing right by ignoring her right away and giving her attention only after she settles down.

A year-and-a-half to me is still kind of a puppy, so give her a chance. How long have you had her, 3 months? I've had my pups for over two years now and they are still crated when I leave the house or even overnight sometimes when Jamie starts peeing throughout the night, even after letting her out right before bed. So don't worry about it

EDIT: Another idea - when she goes inside, ignore her completely. Don't bring any attention to her or the mess. When she goes outside, lavish her with praise and attention. She will learn that going outside she gets attention, going inside she gets nothing. Because even negative attention is still attention to dogs, and all dogs craaaaaave attention. So as frustrating as it will be, I know, just completely ignore her and the mess when she goes inside.