mbear - i understand how you are feeling. She is an adult not a child and thus should act like one. Sure, she has been trying for a few months, but 4 months is hardly the same space of time if for example she had been trying to concieve for 4 years!
You were right to tell her you are upset. When we told my husbands parents, my SIL wasnt home as it was a Sunday afternoon. I expected a phone call, email, sms or anything from her the next day with congratulations (even if she sent it to DH, her brother, I would have been pleased with that) but she sent nothing!!
It was only when we saw her on the Thursday (for DH birthday) after our announcement that she was like, "ohhh congratuations" - I thought to myself how fake! Surely she could have at least rang us!!