I doubt SIL feels offended by anything. She just doesn't want to wonder if she should alert your X to things that you've posted. I wouldn't reply. Over time she can decide what kind of R she wants with you.
me: 42 | STBXH: 41 | T: 18 | M: 10 | separation: Jan 3, 2010 | they deserve better: S7 & D4 current thread: http://tinyurl.com/3y8sxcp .: first breathe, then heal, then start LIVING :.