[Tazer]

Wow, 1971 you sound like the ideal Mom in an open relationship and I you. Coming from the heart of a reunited B-mom my thoughts might not be what you are seeking but here goes:
Please continue to remain open to the possibly of contact from B-mom in the future. As you so lovingly shared, she is probably grieving and since her loss doesn't involve an actual death it's on-going, unresolved really, and may take a long time. A year is really a very short time with all the work she has to do. I placed my daughter in a closed adoption but even if I'd had the option of open I don't know how much contact and exposure I was strong enough to bear those first few years. Most of those years passed in a blur. I needed to find myself first...and I didn't feel worthy of contact with her A-parents back then. In time she just may be able to provide you with all the input you desire for your little one.
In my mind after my daughter was placed her birthday was just that...HER BIRTHDAY; the day I gave her away; before that she was mine. It represented the day I no longer had her as my own. I didn't feel her kick anymore, didn't spend days wondering who she'd look like, didn't worry about labor or anything. It was the beginning of "our end" together. In time it got better but it wasn't a cause for celebration at first. It wasn't viewed as a milestone at first, more like the end zone.
These are just my thoughts, OK? You are doing the right thing by seeking on-line support and most importantly by caring so much. I applaud you. Take Care...Tracy ps Happy Birthday to the Wee- One!