Yes, I literally have NOTHING more important to be thinking about 
My friend has two DDs, 11 and 8. She regularly posts photos of them and of the three of them out and about on FB, and it's lovely to see what they've been up to.
She has recently changed her profile photo to a pic of just her and her eldest daughter. Youngest not included. There were photos of younger DD taken in the same session (other photos posted to an album at the same time) so not as if she has suddenly turned camera shy.
I'm sure she has a perfectly logical reason that I can't think of but AIBU to think it's a bit odd, when you have two children and all your FB friends know you have two children, to only include one of them in your FB profile pic? Or is this not at all unusual?
Please answer, or I simply won't be able to sleep a wink tonight!