Yes! In fact, we recommend it.
We find that when you're adding a narrative, it's useful to imagine you're talking to the older version of that particular child. It gives you a special focus.
Also, your children grow, they may become more interested in collaborating with you to record their own stories. Imagine their delight in opening a video selfie made by them at six or eight or 10 to themselves at 18 or 20.
And finally, in our experience, when your kids are looking at these stories when they're older, they'll be fascinated by their own story … but much less so by the story of their siblings.