Ok, then don't worry about any other labs. You have all the evidence you need.
Now we're in "very good friend" territory. Do you have one who would let you borrow their computer screen for a day so you can attach to your computer and calibrate?
This is rather common with some screens, and it's very annoying, isn't it???? Yes, I think you've done the right thing choosing "normal".
Yes, this also seems like the right thing to do.
Can you elaborate on this? What did you try, exactly?
The only way I know is to add a blank layer then press D to make sure you have black and white swatches, then go to Filter>Render>Clouds. Then go to Image>Adjustments>Levels (not a Levels layer, actual old-fashioned destructive Levels) and press Auto to make sure it's black and white. Then change its blend mode to Screen. Then mask as desired.
Well, it's really not easy to make a face look like it's lit by a small close light source. I don't supposed you'll be able to take the photo again, with a lamp near her?
Thanks.
You must have taken plenty of photos on that day. So you need to look for one where the background is clear in that spot where the background lady is. So you can swap it in, you know?