Hi peace, Think about what it is you want to protect your kids from. I have often been asked difficult questions by my too-wise-for-his-age 7yo - mostly due to my H not addressing any issues with him. Instead of making my H out to be a bad guy, which I think would do more harm than telling S the truth, I've decided that for now, I'd like to protect my S's innocence. Usually, I try to turn it around and ask S how he feels about whatever it is that he's asking me about so he can form his own opinion. Not sure if I'm doing the right thing though...
Your D is much older so I'm not sure how much she understands about the sitch. I believe that the truth always comes out in time. Personally, I don't think it's necessary for her to know the whole truth at this age.