The Heisenberg uncertainty principle for babies states that you can either take a picture of your baby doing something cute now, or see what cute thing the baby is going to do next, but not both.
I suppose if we’re going to be technical and correct, the principle would have to apply only to physical characteristics, and would have an upper limit set on the amount of data you could collect on either characteristic. Like, you can see where your baby is right now while walking, or your can measure her forward momentum, but not both – but that isn’t nearly as fun. My principle above is really the observer effect. Again, not as fun.