I too am in same situation but to be honest it doesnt bother me a jot.We probably like you have a rule that if there is a problem that I dont deal with it and that my dd gets no preferrential treatment.
I taught for four months at DS's school (filling in for a 'sick' teacher). Since I was the only science teacher in school, I taught my own DS and also the children of friends. One of my friends asked me to keep our friend/friend relationship and teacher/parent relationship separate, but the others were all quite happy for us to catch up on social stuff at school, and to discuss their little darlings outside of school (not that we did a lot of this).
This was all made easier by the fact that the regular teacher is not well respected and they really gave me the benefit of the doubt - plus I really indulged the children with lots of practical work etc, that they really didn't get a lot of before.
Now that the regular teacher is back, I keep getting asked if I will tutor their children, but I don't want to do this - don't really want the responsibility of it, plus I now am working in another school.
My DD's classteacher is a friend - knew her before she was a teacher and before DD (9) was born. We don't talk about DD as a rule, and if we do want to mention something, we are both profusely apologetic first. The head of KS2 at DD's school is another friend, and she is always happy to chat.
I think the thing is I have this with three different people, and it makes me feel edgy because I have definately heard two of them being rather 'deep sigh/raised eyes' about some parents and children for whatever reason. They are also very friendly and gossipy with each other.
I don't like this attitude and think it's not on tbh but accept it must go on in the staffroom. I will always wonder if it's done about us too. What if I have a problem or different pov? I would much prefer a completely separate relationship with my children's teachers - a bit like the doctor really! Two of them started at the school after dd so the situation was not this way before she was there.
I have always found it quite tricky to teach the children of colleagues. I had a particularly difficult year when I taught the child of the teacher in the opposite reception class (she had one class, I had the other). He had a lot of problems settling in, partly due to his over-familiarity with the school, and staff. I always tried to be completely professional in our relationship, but found parents' evenings hard. I wish that my colleague had chosen to send her dh to discuss their ds as I would have found it much easier to be up front.
In the end, I had to be completely honest with her, but it caused a few uncomfortable days for us as teaching colleagues.
Whenever I've taught the children of friends, I make a point of never discussing their children's progress with them unless it's a parents' evening or pre-arranged appointment.