Extended gussets for tweens

Hi, all! I could really use some help. My 5th grader started her period a couple of months ago. We had some period undies ready to go, which has mostly been great for her. However, we’ve run into one issue: her dance classes. She wants brief or bikini style period undies with an extra long absorbent area that is good for heavy days (this is the gusset, right?). The shorts styles stick out of her dance class uniform, so she definitely doesn’t want any of those for this purpose. Adult styles are too big for her, so it needs to be teen or tween sizes. I saw older posts with recommendations for a particular style from KT by Knix, but those appear to have been discontinued or something. I see some from Innersy on Amazon, but I saw comments on here referring to them as cheap and good for light days. She will not use tampons. Does anyone have any suggestions for us?