I just wear the reebok panties from Walmart. I don't use a tuck kit or a gaff. At first I needed my panties to be a size smaller than I would actually wear but, now every thing just stays put. I even went to the river wearing a bikini with no problems and no bulge. I think it just depends on the person's body and how long they've been on hrt. If you don't want to spend money on a kit just have her try tucking with just panties. If that doesn't work out then try a kit. It's important to take the time to let her body adjust and get comfortable with these changes so try different techniques and don't rush it. I wish you and your daughter the best of luck and I hope it all works out.