Lighting Questions (photography)

I'm not anywhere near good at photography so please help.

First, I just moved into a house with a ton of windows, so every time I try to take a picture, there's a ton of bright light in the background, is there a way to make pictures look good like that so my kids don't have halos and washed out faces?

Also, I have one really tan kid with dark hair/eyes and one really pale kid with light hair/eyes, and when I take pictures with a flash, my pasty guy like...eats all the flash and glows and my daughter looks all shadowy, lol. Can I fix that?

TIA

Have the windows in front of them if possible?  

And I'm the same with my kiddies, total opposite haha. What type of camera is it? I'm not sure how to fix that one. I haven't had it happen yet.

You could use a white sheet over the window to diffuse the light.

Quoting Life is a Highway ♫:" Have the windows in front of them if possible?   And I'm the same with my kiddies, total opposite haha. What type of camera is it? I'm not sure how to fix that one. I haven't had it happen yet. "

There's windows on every wall. Which I love, but I haven't gotten many good pictures since we moved, lol. And it's a canon powershot sd790. It is old and nothing special. I don't try to take professional looking pictures, just pictures where I can make out my kids' faces, haha.