How to reduce/remove sun glare and light streak

A couple of things Trevor didn't mention (although he does them excellently !)

You can bring out facial features (eyes mouth etc) naturally by duplicating the layer and setting the uppermost to multiply. Then use a mask to lightly reveal the features.

When brushing try not to exceed the resolution of the image - it can look unnatural to see every detail on the re-touch but have them blurred on the rest. The mixer brush is good for softening hair which you have drawn with a small round brush.

Use noise to help blend. To do this duplicate the final image and add a fair bit of noise. By using a mask you can introduce the noise into the retouched areas which make them look more natural.

Don't overdo the retouch - keep it natural as possible.

Here is a brief effort :

Dave

There isn't enough information there to fix with Photoshop tools, so the best you can do is get it as close as you can using things like De Haze, Contrast, and Clarity, and paint in the details by hand.  I guess that is not an easy thing to do without some practice, but it is not too hard, and it is a lot of fun to do.  It does take some time though.

This needs more work, but she who must be obeyed wants her tea, and she gets scary when hungry.    All the detail (so far) is painted in manually using just two brushes.  Round pressure controls size, and the hair brush from this set.

Skin and Hair Texture Brushes by castrochew on DeviantArt

The secret to painting hair is to lay down the darker tones, and then paint in the highlights.  About twenty minutes to get this far, but I'll be in trouble if I don't get to the kitchen!  :-)