What about a book?
'Well-adjusted babies' (j. barham-floreani or something similar) is into holistic wellbeing (written by a chiropractor, actually) and it talks about birth, and gentle parenting etc.
It seems like it might fit?? Might be a bit $$$ though if you already have things prepared.

How about a jack-n-jill toothbrush and jack-n-jill toothpaste?