I don't know your sitch iwitw...but replying wise my rule is if she asks a question I'll answer it very briefly, if it's a statement then no reply needed.

For example, in this case I'd say "Car's being fixed, I'm fine, tell d9 I love her and not to worry- thanks"

Me: 35|WAW: 38|D: 6yo | http://tinyurl.com/2dxx7m6
Feb 2006, left, came back in two weeks
Aug 2006, left again
Apr 2007, filed for divorce
Dec 2007, reunited
Mar 2010, moved out, filed again