My lazy sister-in-law that doesn't care about her 3 year old son ACS professionals and people whod been victim

She has a 3 year old son that shes taking really bad care of. 1 she hasn't taken him to the hospital to get his shots since he got his 1ST set of shots(3months old) his teeth is ROTTEN his teeth is shades of brown black holes some of them is broken,chipped and he says OW when he eats a french fry AND he has a huge pimple on his gums on the top. No effect. She dont buy him bottles regulary his eyes look black. He DOESNT EAT one time she told me he hasn't eat anything in 6 days only bottles.. (that got me mad) he squints at the tv hes in bad health and im more concern about his teeth she don't listen to nobody this ***** is fuccing 24yrs old. Just wanted to know what can I say to her that can scare her. I mean ACS already comes to the house because she doesn't take her sister to school and she tells them that she don't live there so theres no reason to file an complaint.. and ACS hasn't seen his teeth. I know they would take him for that right?