Obviously it happens, but some days the difference is more noticeable than others. Sometimes it’s something very specific, other times, for some inexplicable reason, they look different. Older or more mature, somehow.
My husband and I have always marked these occasions by commenting to each other, “She got bigger today.” Well, I guess they’ve synced up their growing or something, because today, they both got bigger.
For the older one, the difference is obvious. And she looks bigger now. For the younger, I don’t know what it was today in particular, but she definitely got bigger today.