For starters, I would NOT take her to the gynocologist. That would be pointless and fruitless and would make her think she is "sick" because she got her period.
I would simply "go with the flow" (oooh, pun NOT intended). Don't make a big deal of it, except to encourage her, especially if she gets cramps. My daughter found that motrin worked better than midol for cramps, BTW.
I would buy her pads and always be sure she has enough, so she doesn't have to ask, and just see what happens. It might be sporadic, but then again, it might be very consistent right from the start. Your best clue is probably to think back to when yours started. I'd also buy her some lightdays types of pads so she's able to use them when it's ending.
If she has a wonderful female teacher, you might want to let her know, and the school nurse, so they can provide assistance should it ever start at school.
Just treat it like a normal everyday thing, which it is. Find a way to make it "special", so it isn't the dreaded curse kids called it when I was younger.
And if you talk with the school nurse, I think you'll find she isn't the only one who started her period early. Some do, and some don't. It's kind of a wait and see kind of thing.
Most of all, just enjoy her. Relish these years, because getting your period is a reminder for you that she's growing up. In 4 years, she'll be in high school, and 4 years after that ? It's a wonderful adventure to grow up with your children ! Enjoy !