Hey, new here.
I think a lot of MIL/DIL issues stem from a couple of things.
one is expectations, 40 years ago a wife's duty tended to be stay home and take care of the kids and cook and clean. Now you can add on to that possibly working full time, running kids to all sorts of different activities, spending time with spouse, making yourself a better person, doing all sorts of extra activities yourself. It's a lot of stress to try and balance that and still be the perfect mommy or wife or DIL. When I've mention to my mother the stress I'm going through (and I'm a SAHM) she's been known to say something along the lines of 'well I did that (kept my house clean, did my grocery shopping.. etc) all with 5 kids...' Implying that I shouldn't be stressed about whatever it is. And that is just with my mother, I take it with a grain of salt and just don't mention those types of things anymore. I know my mom doesn't mean them in a negative way she's just trying to understand the differences in our decades. I can also see that if something similar came from a MIL said in the same way not trying to be mean could upset a DIL and make her feel inferior and judged and no one wants to spend time around where they FEEL judged.
Another issue that I think plays a big part is all the social networking things. 20-40 years ago the only means of contacting your family were phone calls (and if you weren't home there wasn't an answering machine to take a message) letters and visits. So if you missed a call you never knew who called or how many times. Visits were at holidays and generally not that often because travel was hard and/or expensive unless you lived in the same area. Now I think people get a little freaked out at all the ways to keep in contact, facebook, cell phones, email, twitter. Sometimes it's just information overload and people just need a little bit of privacy.
Also @penstamen I have a similar story that might help you.
So my dad was 43 when I was born and went through a depression episode when I was a young teen. For a long time it was hard to talk to my dad as he never said much of anything I love him but it's been a hard road to have a close personal relationship with him. That said when I got married I liked my FIL he was a nice guy, I just didn't really know how to interact with him as a father figure. He was always concerned and asking my DH if I hated him and what he could do to fix that. My DH would always tell them that I didn't, and it's been tough to try and create that bond with him when I had such a hard time with my dad. I think I've been able to make him feel that I don't hate him, I don't know because my DH hasn't mentioned it in a long time. I hope that helps you feel at least that it may not be your fault and that she just has issues with her parent's that are sadly affecting your relationship with her. And that in time a better relationship can be worked out.