To date, our kids don't know I crossdress. They don't have a 'need to know'. I have no desire to dress in front of them, and doing things with them in support of my femme self isn't something I want to do either. So, no 'need to know'.
However....that can change.
When they move out, the possibility of discovery will actually go up because of the situations you describe Maria. If that becomes a problem, then I will likely tell them. I don't want to spend the rest of my life in hiding.