Dd is 8 and ds is 6- they share a room and have bunk beds, but no one ever sleeps on the top. Any one else have mixed set siblings sleeping together? Any thought son when this may become innappropriate?

My ds was about 9 and my dd 6 when they stopped sharing a bed. Same thing they both slept on the bottom. My oldest pretty much stopped it, he wanted his own space, my dd however would still sleep with someone if she could lol and she will be 9. My brother and I shared a room until I was 11 or so and a few times a week we would get into the others bed to talk and keep each other up, he's 4 yrs younger then me. My two girl cousins who are in college still sleep together when they come home on breaks. Last night my ds 11 and dd 3 slept together. For our family it's whatever each feels comfy with.