Feminine Hygiene Help!

Long story..

my mother in law showers but not every day. She looks disgusting and her hygiene is awful. She stayed with us last night because she didn’t want to drive home she had extra clothes with her.. she got up changed left her dirty panties in the bathroom floor didn’t brush her teeth or comb her hair and left to work. I was cleaning I found her period blood underwear, just on our bathroom floor 🤮🤮 she came home asked if we had picked up her “clean clothes” from the bathroom I said yes it’s in that bag.. after that she was walking by me I could smell her being on her period and even my boyfriend said she needed a shower she said “it’s to cold I’m not gonna shower” She never showered and smells bad all the time if it’s not fish smell it’s period smell, how can I tell her she needs to care for her personal hygiene with out feeling like I’m being rude (even though I am)

Update!

I told my mother in law about her dirty underwear, and how I didn’t think it was right for her not to shower and take care of herself. She took it pretty hard and started telling me how I’m a disgusting person and it’s none of my business wether she showers or not. & if she’s on her period it’s not my place to tell her to shower ether, she said she’s grown and will do with her vagina what she pleases..

I said ok do what you want but in my house I expect you to respect it and not leave your dirty underwear laying around because It’s not her house and she could have the decency to brush her teeth if she’s gonna be kissing my daughters hands since I told her she isn’t allowed to kiss my child in the face. She threw a glass of water at me and grabbed her stuff and left. My boyfriend called her mad and said if she couldn’t respect me she wasn’t allowed over here anymore. And she said if you choose her over me forget you have a mother and hung up the phone