Hmmm, as YesDear mentioned, fixing this photo is going to be very, very hard. You're going to need someone who's much more than just "good at photo editing."
A photo like this, where there is "missing information" (ie. the bright white flash "erased" many details of the photo), you'll need a photo restoration specialist. This would be a professional who is extremely proficient at Photoshop who can recreate some details into that photo. I'm sure you've seen examples of torn, wrinkled antique photos that are "magically" restored to mint condition. That's what a photo restoration professional does.
Another idea would be to create a composite photo, where you'd "transplant" 2 new heads (1 for Pocahontas and 1 for the girl) and maybe rebuild the part of the background area where the flash "blew away" the detail. You probably have similar headshots / poses of the girl. There are probably other photos of this Pocahontas floating around on the Internet. And you can probably find other pictures of the background, too. Combine parts of these 3 into your original photo using Photoshop, and you can come up with a potentially convincing composite photo!
You can maybe darken some of the streaks of light to get some detail back on both faces...but only up to a certain point. The flash in the middle has "blown away" much of the detail in that center area, which would be very very difficult (if not impossible) to recover.
I'm sure there are other ideas out there on fixing this. I don't think I have any easy answers.