Step Mom and your daughter’s menstrual… advice?

So your 13 y/o daughter spends time at her dad’s house where her dad and his girlfriend live together. Your daughter has an accident with her period and has some leakage on the sheets. She seemingly is shy or embarrassed to say anything and leaves the stains on the bed and returns home. As a mother, would you want her “step mom” to have a little talk with your daughter and resolve the situation right there? Or would you want “step mom” to inform you so that you can have a talk with your daughter yourself?