Messedup You are so not being unreasonable, and definitely not reading too much into it. Your "friend" is a disgrace. Even if she's so weak that she's ready to jump ship and play with her new friends, she should have regard to your feelings. How exactly is she disappointed in you I wonder? Two examples to share with you.
Friend of mine, divorced, ex utter narc, dd seeing a psychiatrist as he's messing with her so much. One of her closest friends and her husband are still "mates" with the ex, occasionally socialise, always chat with him. My friend grins and bears it, but told me it makes her feel like they don't really take her seriously. It's as though her ex's actions aren't really that bad to warrant them walking away from him.
Another friend, closer to me, went to hell and back last couple of years. Unimaginably sad time, we were joined at the hip throughout. She had a lovely family day out with my ex and kids, couple of other get togethers. And had the nerve to try and counsel me as to how to maintain some sort of communication with him. I seethed underneath. Then one night when we were due to meet up in a group, I texted the group and said what she'd been doing, and said I wouldn't be there. She found out why, wrote a long letter of apology, and our friendship has started to repair.
Her actions really brought me low. It made me distrust my friends for months. I now just have much lower expectations. I don't think most people have the nerve to turn away from somebody else's ex, even when they know the backstory. They don't have the courage. Ultimately they don't want to rock their world, let any of the nastiness in. So, if you have to pay the price, so be it. It's complete rubbish.
Isain - are you meeting with your solicitor to try and agree what the contact will be? My dc are older, so I don't have any advice as to what you do in these situation with such a young child. I know others on here have been (and are going) through similar though.
2012pp - yes, it's shocking isn't it, I'm gobsmacked at the lack of self-respect these men have. I know they don't see it that way. But really, if you had any self awareness, you wouldn't want to be viewed as a selfish, immature bully. It's troubling how little regard they have for their dc's welfare. They literally don't see them as a separate individual. They just view them in relation to their own lives; what can this do for me, how can I use them to help me get what I want. Shame there isn't a narc sterilisation programme. Put me down as head nurse !!