How do i make my lil sis take a bath?!??!she smells like $hit!!!!!?

she is 9 years old and she hasnt taken a bath or shower in over a MONTH!!!!! she has BO so she stank like H3LL!!!!!!!!!! apparently she is trying to break a cl record -__________________- ive b*tched her out to take a bath or shower and how much she stank and she refuses to take a bath til she breaks this record!!!!! help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! SHE SMELLS LIKE $HIT!!!!!!!!!!! from 13 year old girl with a nasty STANKY lil sister