Child development sites raided, timeline hammered out (starting at one year old and progressing to 13), and I even got notes on what to feed a baby and when since I have zero experience at this whole child-rearing thing.

I'm writing fantasy again (I generally do that or science fiction). As per my usual, I have some very long lived magical characters wandering around with the average mortals. In this case the main character is now an old magical character and she's going to collect on a favour owed to her by an old friend. The friend pays up... with a baby. This is not what she expected to deal with in her declining years. :D

So the themes are pretty much as you would expect, growing old, growing up, and being very careful about asking and lending favours.