Don't remember how old your kids are and I know TIF's are younger. Yes they do notice stuff, more than we realize. If they feel comfortable enough, they will tell you what they think eventually. Again though, it depends on their age and how able they are to express their thoughts clearly.
My S, God Bless his heart, is my savior on some days. He allows me to see the humor in this, allows my frustration and shares his with me. He also has shown me my errors and has actually said things that make me see that he understands how blind his father is to things sometimes. So I love that he is the age he is. We have a lot of fun together and I think we are both helping each other through this. No he doesn't know all of the ugly details, but he has seen enough with his own eyes and ears to know this is all nuts.
For me, that is the hardest part in all of this. Because I do not want him to come out of this damaged and there are times when I have to wonder if D would just be the best thing for him. I don't think it is but there is definately a fine line.
"Acceptance doesn't mean resignation. It means understanding that something is what it is and there's got to be a way through it."--Michael J. Fox