Seems like it is one of those times where she just needs a reminder.
I can (vaguely) remember having just had a baby and having "baby brain". I was so out of it I wasn't really thinking clearly. I can picture myself during that time doing what your friend is doing, more because I was trying to share my joy and not thinking in depth about anything.
Also sounds like she has been baby focused all along and since it was fine so far, hasn't realized that it might be a problem.