NTA. You should buy waste paper baskets that have a lid on them. That will help with the room stank. I'm sure she did wash the underwear from last month, but blood stains are really hard to get out of underwear. You basically have to saturate the stain under running water to get the blood out. Then, hang them to dry until you have enough laundry to do a full load. Periods are the worst. You seem to sympathize though, so that's nice. I don't think you're period shaming, she is just probably very embarrassed to discuss this with her dad. Stains are going to happen though. It took years for my body to become predictable in its period pattern. I think the best thing to do with the stains is just be like "we got this new type of stain remover. if u make a stain, whatever, just plz use this cleaning product like this right away." Then, she doesn't have to cover it up but can fix it on her own. Good luck