It definitely sounds like you might need to check this out.

How about the other times, does she have trouble breathing with her nose? I would get it check with your GP.

Funny! But can she breath through her nose normally?

Does she breathe with her mouth most of the time? It is not natural to breathe with your mouth unless your nose is blocked, maybe you should go to a Dr to get it checked out, better safe than sorry.

lol. maybe you could get that checked though especially if she always seems to be breathing through her mouth or sits there with it open.

I was wondering if she has a sinus problem too

Maybe you need to check whether she has a sinus problem.

Maybe worth speaking to the GP or someone like a speech pathologist or ENT doctor? They made have some helpful advice. All the best!