When she says how tired she is and that you can't imagine.. I'd probably respond with something like "Yes, actually I do understand... I am so tired all of the time that it is precisely WHY I don't have a child yet...because I am already too tired all of the time. I guess you understand how I feel pretty much everyday now!"

I hope she'll come around sooner or later. And that her baby still start sleeping longer stints so that she'll feel less tired and less likely to need to vent about it. When did you mention the PTSD to her? Was it before she as pregnant, during pregnancy, or after having a baby?

If she doesn't really understand PTSD, and you disclosed while she was going through one of the biggest changes in her life... then she quite probably hasn't registered it, or processed it. I don't think she's ignoring that about you on purpose.

With that said - I would be feeling really upset too. In fact, I actually totally get it. I spent two years living overseas... and during that time my friend became pregnant - which she didn't tell me about because she figured that everyone was finding out via word of mouth. I was like "... how could I know? We don' have mutual friends and I live across an ocean." I was really hurt as we've been friends since I was 9 (officially 20 years as of this year! so that that point we'd been friends for like... 16 years..). This is my 5th year since I left to go to the UK... and you know what? She's never once asked how it was for me there. She never asked anything about me during the two years I lived there, and even since returning and seeing her a few times? She has never, not once, inquired about my life. I've sort of given up and that hurts me a lot. So.... I understand the hurt that you're feeling.