Only does naked wees 🤦🏻‍♀️

We have been potty training on and off since 18 months and we have gotten to the point where she will do wees on the potty 🙌 However, she will only do it when naked. I'm just kind of wondering if anyone has any advice about where to go from here. We tried her choosing her own underwear and that didn't work. Also with poos, she doesn't seem to know when she is going to pop like she does with wee's. She just watches it come out of her bum and panics. Is there anything I can do to help her with this? She currently has a pom pom jar which when she fills she gets to choose from the prize bag to reward her for going to the potty but I'm at a loss 🤷 Thanks for the advice.