Niece and nephew are really bad.

So I'm not their parents im their uncle. I'm really concerned for my sister, their mother. My niece (aged 14) and my nephew (aged 16), Basically do what ever they want. My niece recently left the house and ubered to an unknown location and spent the night there. She maxed out my sisters credit card buying random things. When I saw her last week she had hickeys on her neck and is constantly trying to be out and about. My nephew basically does that same thing only he used my sisters card to buy himself new clothes that was like 300-400 dollars in total, just because he said he needed new clothes. She doesn't know what to do. Shit I don't know what to do. They have everything they could want, their own room, food, basically anything that makes them comfortable yet they choose to be disrespectful. Talking to them doesn't work. My nephew recently got put into home schooling because he was literally too lazy to walk to school or take the bus, if he didn't have a ride to school then he wouldn't go. My niece got kicked out of school for fighting. Their father is not in the picture. My sister divorced him because he was abusive. It pains me to see my sister like this knowing her kids are just terrible and she vents and cries to me and our other siblings. Like her kids don't see what they're doing to her. Any advice would be appreciated. via /r/Parenting https://ift.tt/3pzOtt7