Yes, but our school has 4 different "pathways" in one iyswim, (not UK) and she is in a completely different one to me. I catch sight of her in the corridor and she ignores me 
I am lucky in the respect that I don't teach classes with any teachers that she has, so when there are parent meetings, I am just another parent, quite rightly. Nor do I ever speak to any of her teachers about her outside of the allotted time for parent-teacher meetings.
We do have other teachers' kids at school, and nine times out of ten it's a disaster, because the teachers come to the school, or put their kids into the school specifically so they can be there together. I've heard people actually say "I came here because dd is here" or they have pushed to get their kids into that school, into that specific class.
A friend of mine has found herself in serious hot water at the school she teaches at, and where her sons are, because she is always getting involved with parent stuff, because the parents are the parents of her sons' friends, but in her capacity as teacher (giving out info she shouldn't, adding all the world to FB etc etc) She has had a disciplinary after another parent complained about her.
It's not a fine line, it's a great big whopping one, but unfortunately, when our own kids are involved, it's hard. Dd will tell me stuff about one teacher in particular and I just grit my teeth and think "he'll be retiring soon, he'll be retiring soon".