Go naked! LOL. Rushed answer - but I'd get cute underpants for her to try on - and reward her with if she succeeds. Let her pick them out - even better.
I was fortuate to have my daughter mostly potty trained at her daycare. To get over the hump at home, I let her go naked around the house for 2 days. And we'd rush to the potty and cheer real big when she peepee'd in the potty. it became a big game that she loved, and then we both knew she could do it if she wanted to.
Put towels on the couch - ok to put a diaper for naps, but otherwise naked at all times at home. You can work on clothes as a next step. It's really less mess than it seems.
If you're going out, you can try putting the underpants on under the diaper and talking about keeping them dry and letting you know when she has to go. To get over the hump, you have to let her go EVERY time. No - 'stuck in traffic, just go in your diaper this time'. I had to whisk off a highway once or twice, and quite a few times she dropped them in the woods or even a parking lot between cars, but it pays off, and passes quickly. Really :)
Note- time to get rid of all those snapping onesies. It about killed me because I finally had so many I liked, but "they're for babies who wear diapers". She can't get them off so it mixes the independence message up. (some that I loved, I cut the bottom off of so she could where as shirts ; )
Good luck.