When posing three girls (or three people, for that matter), I always try to make either a triangle or diagonal line.
I thought it might be fun to take a stroll down memory lane and look at some examples.
Of course, when they’re little, it helps to give them something to do… and someplace to contain them if they’re prone to crawl off:
I especially love this one where their eyes are lined up…
They don’t stay little for long.