Sorry if this is not best place to ask but always seems to be good advice on AIBU boards 
Background - my sis has 3 ds age 9, 7 and 5. She is a single parent due to domestic abuse. Their dad had non molestation order to prevent him seeing my sis and was only allowed to see kids in contact centre.
All this then expired and courts agreed he was allowed contact on a weekend for 2 hrs.
Kids behaviour has never been good but it's now beyond ridiculous. My sis is trying to keep it together but they are so naughty she is seriously on the brink and I don't know how to help her.
It's sad for them as they've obviously been through and seen a lot and it's still ongoing now.
In the mean time does anyone have any tips on how she can get kids to be better?
They fight like animals. They're rude and obnoxious. They have no respect for each other, strangers, family, toys, her house etc. She can't complete simple tasks such as a quick trip to the shops without them completely embarrassing her as they literaly will rugby tackle each other to the floor and wrestle until they're physically pulled apart which is getting increasingly difficult with the 9yo for my small sister.. They'll bash into other people, scream and shout like a heard of howler monkeys. She has little money but what she has she'll treat them to trips to theme park, swimming etc and always ends up having to leave as they're so bad.
Threats down work. She always follows through eg. She took them to buy new school shoes and said if they were good they could get a macdonalds after. They were awful so they went without. They were pissed about it for all of 20 seconds. They've been on an xbox and tablet ban for almost a week - they don't care. It's counter productive because without stuff to do or places to go they're worse behaved than before! But how else can she punish?
I have a 2yo and a 3 month old so don't feel in the best place to be offering to take them off her hands because to be honest I can't really deal with it for even an hour so I don't know how she's getting by day to day!
But even if I took them for an hour it won't solve it long term.
Worth adding middle son (age 7) is query SN for autism. He has very bad ticks, laughs hysterically constantly (like a nervous thing) and has to be bashing something all the time but he is also incredibly bright.
Please help!