Question For Any Female Tennis Player?

I am a single father to a girl who just turned 14. There is no "woman of the house" to help me with this situation. My daughter has issues playing when it's her "time of the month". Unfortunately, there isn't a magic date she can circle on the calendar to prepare, they just happen. This past weekend she played in a USTA tournament and made it to the final. Before her match is when it started to come on and I had to drive to a Walgreen's to get her pads. She was out there in the match holding her abdomen at times from cramping and really sluggish. She says it's harder to move around quick on the courts during the days she has them. I told her before the match she could default and not play but she wanted to anyways and lost 6-0,6-0. Which is unimportant the result it was also 90 plus degree day, so not ideal conditions. Will this get better in time or is there something I can do or she can do to help ease her pain during a match. She refuses not to sit out a few days and with her first high school season coming up. I hate to see her grind it out in pain and have her playing matches important to her since she's already been guaranteed a varsity spot by the coach. Thank you in advance for any advice.