I don't understand how someone can let them move in with them have them on the lease have them but…

I don't understand how someone can let them move in with them have them on the lease have them but food for the house and you still constantly threaten to kick them out. For example a friend of mine (we'll say her name is Stacey) lives with her grandma. Her grandma said Stacey and Stacey's boyfriend can move in with her. Stacey's grandma forces Stacey to get on foodstamps to help with food but Stacey and her boyfriend don't have to worry about paying any utilities as long as they clean up after themselves and help her out when needed. Stacey gets on her grandmothers lease. Her grandmother tells Stacey Atleast once a week to find another place to live. Stacey's grandmother doesn't allow Stacey or her boyfriend to do cloths in her washer so her grandmother does her cloths for them. Stacey brings $200 worth of foodstamps into the house, cleans all the time, gets a shower once a week (if that because her grandma yells about the bills being too high). Stacey has no where to go not even a family members so that's not an option. What else can Stacey do.? She goes to get family members house once a week, gets out of the house as much as possible, and her grandma still threatens her 24/7 but says once a week she needs to find somewhere else to go.