During the working week, our alarm sounds at 0615, but we're used to Elizabeth waking up at 0600 precisely - and weekends are no different. Usually she starts the day with some gentle burbling, and only starts getting grumpy if she gets bored.
Sometimes, her burbling takes the form of what we've taken to calling "singing". And so it was on Saturday morning:
[descending scale] Da da, da da, da da, da;
[repeat scale] Da da, da da, da
Suddenly I realised, that's "Twinkle Twinkle, Little Star"!
She's done it a couple of times since, and at breakfast on Monday I was able to make out the words "little star" as well. We've probably been a little remiss in singing nursery rhymes to her (though we sometimes play CDs in the car), but I guess the nursery have been teaching her.