Anybody else with a female tween impacting YOUR cycle?

Ch

My 12 year old hasn't started her period yet, it will soon enough, anyway, I only have my kids a week at a time, every other week. My period has been pretty solid at a 35 day cycle for 8 years. In the last 6 months, if I'm due to start within 6 days and my daughter comes around, it'll start within 18-hours. I'm not exaggerating.