our regular sitter has been here every saturday for 14 months and i swear she knows

ok so we have this amazing sitter, shes 22, uni student, lives like 4 streets over, kids ADORE her. shes been our saturday night go-to for over a year now. F36 dh 38, two kids 6 and 9, weve been LS for about 18 months and basically our entire date-night infrastructure is built on her existing. heres the thing tho. the first few months we'd come home at like 11.30, very normal dinner-and-a-film timing, pay her, all good. then it crept to 12.30. then 1am. last weekend we rolled in at 2.15am and she didnt say anything but she gave me a LOOK when she was putting her shoes on. not judgy exactly. just... aware. dh is convinced im imagining it and that she literally does not care, shes a 22yr old getting 18 quid an hour to watch netflix in a house where the kids are asleep by 8. and rationally i know hes prob right. but i keep thinking about the wristband incident last month (long story, found a club wristband under the sofa cushion when she was here, she handed it to me without comment) and im like... she has to be putting some of this together right?? ngl part of me doesnt actually care if she knows, shes an adult, shes not gonna gossip in a way that would get back to anyone we know. but the other part of me is like, do i need to come up with a new "we're going dancing" excuse, do i need to start rotating sitters, do i just keep my head down and accept that the person watching our children prob has a theory. anyone else have the one good sitter who has prob clocked it. how do you handle it. or do you just not.