I'd be ringing Thomas quietly, too. I'd say that I was about to gush about it on Facebook (or to Angela, whatever works best) and thought that you might ruin a surprise she's going to get, too. Tell him that if she's getting a gorgeous "first artwork" then you'll sit on your excitement until after Christmas so the joy of the surprise is not ruined.
If for some reason he hasn't done something (and if he was cagey about the paint under the baby's nails then I'd be surprised if there wasn't something special hidden away!) then he has time to get it sorted and make it amazing.