Husbands family taking advantage

Edit: **They’ve been living off of her before I was even in the picture so over 12 years now, never lifted a hand to pay for anything **

SORRY ITS VERY LONG:::

I’ve been married to my husband for 4 years. We have been living in a mobile home on his grandmas(84) property since we got together. We pay 400$ a month for water and whatever else she wants to spend it on. She usually refuses the money we give her because my husband helps her with anything and everything. She relied heavily on my husband for repairs, remodels, projects, yard work, etc. being that we live(ed) on the same property right behind her(she has 2acres of land). He has never complained & always jumped when she wanted/ needed something. They have an really awesome relationship because she basically raised him . However, she ONLY asks my husband for our help even though her son(58)& his wife and their kid, her daughter(52) & her husband, and other grandson(29) and his wife and their kids , ALL lives on the land too. Total it’s 12 people living OFF OF HER. We moved 8 months ago because my husbands job is now out of state and she calls us EVERY SINGLE day crying how they are taking advantage of her, they are ALL refusing to pay for their own utilities, never wants to help her, and to top it off nobody is working! She asked them yesterday if they can help her with 200 for electricity and water that their using in her houses (she owns 2 houses on her property & they live there rent free). They drink and smoke weed all damn day. She is begging us to come back and idk what to do or say. It angers me how they can take, take, take from an old lady but it’s a problem if she asks them for help financially or physically. It sickens me but there is nothing we can do as of right now. What can we do to help his grandmother?? She refuses to kick them out because it’s all her kids and grandkids!