Speak No, See No

My mother in-law's nonverbal communications often leave me confused.  I usually feel confident about interpreting nonverbal behavior, and if I am not sure, I gently respond in such a way that triggers a feedback that clarifies the message to me.
Anyway, this is far from being the case when it comes to my mother in-law. I know her for 12 years now, and yet, every time after I share information with her, which is solely about me,not including her son or grandkids or anybody else, (such as, what classes I am planning on taking next semester, or that I am thinking about dying my hair darker, or that I got my blood tests results…) every time she respond to me with silence, and she also avoids eye contact.

This nonverbal message is very much open to many interpretations. After 12 years, I am still unable to decide what this message means, what is she telling me?  Sometimes I think, maybe she did not hear me, but if I right then say something about my kids, she responds immediately. Sometimes I think that she does it because she does not like me, but she always seems to enjoy talking to me; she shares her information with me, and she even asks for my opinions and advices.

It was finally few years ago, when I decided to just stop trying to interpret this specific nonverbal behavior, and since then I accept it the way it is; I mainly hold back from talking about myself when I am around her, but if I happen to do so (which as I said always lead her to be silent and to avoid eye contact), I just acknowledge my confusion and leave it at that.