Question about baby gift

[PamNY]

I'm buying a gift for a baby who is four months old. It's a just-for-fun t-shirt, and I can't decide whether to get 6-12 month size or 12-18 month size. I remember hearing friends say that many baby clothes are too small.

I don't have kids and most of my friends are years past childbearing, so I don't have anyone IRL to ask.

Here's the shirt, so you can see how not serious it is.

Pam