Putting thoughts in her head
Okay, it was a real temptation just to leave it at that.
I've seen this image knocking around the web but I have never read the comic (or comics - Greg Land isn't too proud to reuse an image he's photoshopped) it's from, so I have no idea of the context. And I was trying to work out what could possibly be going through the mind of Sue Richards to occasion such an expression.
Here's a few of my attempts to define her mood.
Try it yourself. It's fun.