Background: DN is in her mid 20s, up to two years ago she lived with PILs. Rest of the family has been NC with DN mother for four years as she's narcissistic and takes it out on the children in the family.
DN decided to move back in with her mother, all was fine. DN said she'd still see elderly PILs and rest of family.
DNs behaviour instantly changed after moving, she stole from PILs using their debit card to buy things online, she'd regularly phone and text PILs and other family members giving them abuse (we believe her mother was sat next to her telling her what to write as it's her type of wording if that makes sense). She had a strop when nobody sent her any birthday money. Accuses family members of lying about really simple things and makes huge dramas despite lying about most things herself.
She falls out with everyone for a few months and then pops back up acting like nothing has happened and it's really stressed everyone out. There's a lot more but I don't want to be outted.
She's popped up again expecting to come see everyone and to everyone to forget about her past behaviour.
AIBU to say I don't want to see her as no doubt in a few weeks down the line they'll all fall out again?
I really can't be bothered with this, never know where we stand with her, I also believe it's not fair on the children as they're getting upset as one minute all is fine then they're confused why she's dropped off the face of the earth (saying she's working isn't fooling them) or am I being unreasonable as she's my niece and I should be the bigger person?
I just need some perspective please.