Probably nothing more than a cute quirk, but have you made sure there's no skin irritation or condition she's fussing with? I used to raise Russian Dwarf hamsters and Chinchillas they will pull their hair over their face (as much as they can with short furr)-more like they "puffed" themselves out when they had gotten too many "warming foods" which is pretty much grains-do you feed with a food with corn or even brown rice? I wouldn't worry too much of it but I'd double check sounds like a lot of Yorkies do the same behavior-Elvis sticks his tongue just barely out of his mouth when he is relaxed-I thought it might be hurting him because it looks as though he's biting it but every time he's comfortable stretched out or falling asleep-just barely his lil tongue pokes through, it's pretty cute too. You could try a pup cut...short over the eyes. My mini schnauzer has massive (she's a mega coat) eye brows that grow right down over her eyes-she navigates just fine-even when running crazy
)