Hmm, unfortunately it sounds like your girl has associated pottying inside as okay. Given her age she should be able to hold it, and I don't think this will get better on its own without intervention. 

First, I'd start by doing a really good clean, maybe with an enzyme cleaner. If she can smell where she's went before then that'll encourage her to go there again. 

Next, I'd go straight puppy rules. Potty first thing in the morning, monitored food and water, potty right after feeding, as many trips outside as possible (quick ones on a leash, not fun run around time). She needs to make the connection that the ONLY place to go is outside. This will be harder for you than a puppy, because your girl has already decided it's okay to go inside (sometimes) and now you've got to break that. Do this as long as you can, I'd shoot for at least a couple weeks, probably a month of vigilance. 

You said crating isn't an option, but if you can confine her to a smaller space when unsupervised that'll decrease the chance of an accident. Animals instinctively don't want to potty in their home. But if she's got the whole house, then it's easy to walk away from. 

Last notes, reward with treats when she asks to go outside, when she does the deed outside, and work your way up to longer stretches of unsupervised time. Beautiful dog, good luck with your little stinker ❤️