How to tell someone to be more clean

How to tell someone to be more clean with themselves and shower and brush there there teeth so I live with my grandma and she could last a whole year without taking a shower and doesn’t brush her teeth she drives and is able to to shower she doesn’t have any physical problem but it just bothers me how she doesn’t worry about her self she sometimes really stinks how to nicely tell someone they need to be more clean with there body?