yabu but you're not weird for thinking it, just not what you are used to
lots of bed sharing in our house, eldest is a young teenager, one is a girl, and sometimes all three go in mahoosive bed together, lots of random mix-ups when dh or one of the children is away
they just talk and then they conk out
there is no cuddling, god, they fight a LOT during the day, but they just read, talk, sleep, sometimes put pillows down the middle of the bed, as in "that's MY space, get on your own side" etc etc
I am just wondering about the too old thing though
Anyway with Grandma, six and eight, it wouldn't occur to me to be troubled, in fact anything under 10
over ten I would think, maybe not