Buy a crate.
Start by putting her in the crate when she's very tired and leave her to sleep in there. If she screams blue murder, DON'T open the door until she's quiet, even if its just cause she's stopped for breath. Feed her in there too, just make the crate a good place - give her extra treats and new toys in there. When she'll happily go in the crate, you'll find it easier to housetrain her. What breed is she?
Puppy in the crate for naps regularly, then she wakes up, straight out to the spot, give a command as she goes (in our house its "go pennies"), lots of praise and then into the house for games etc. She'll then be "empty" so you know she's safe. Then, every hour onwards from that time out, take her back out and give a command when she looks like she's going, big praise and repeat. If she doesn't go, take her back inside but watch her like a hawk for the wet pants look, then grab her, outside to the spot and command then big praise, and in again. This has 2 good outcomes - she'll learn her spot, and she'll also end up learning a command that she'll know means go to the toilet, so at night etc, you can give it and know she'll go and not hold it in. Its useful on walks too if you've only got time for a short one and by the end she hasn't gone on her own. The crate also helps as it becomes her den, and she'll instinctively try to be clean and dry in there, so you can pinpoint her full bladder better to get a command and make her housetrained
Does that make sense? Its a bit garbled but I can explain anything else if you need me to.