My new plaster pool is COVERED in green stain..

[waterbear]

I did read a post on metals in pool water and crushed vitamin C in a sock. IT WORKED ON THE STAIN WITH LOTS OF RUBBING.

This is setting off warning bells for me. Vitamin C (ascorbic acid) works on metal stains by chemical action (reduction) and does not need rubbing!
Algae often needs a lot of rubbing to remove it.
Metal stains don't rub off unless you rub hard enough to removed plaster.

The other red flag is that the problem started after your daughter's sleep over, which very likely created a low chlorine condition in your pool! You also stated that the stains are not as dark in shaded areas of the pool. Algae needs sunlight, metal stains don't.

I suspect you are seeing green algae on fresh plaster.

Try holding a chlorine tablet on a stained area for about 10 minutes and report what happens. (wear rubber gloves or use something to hold it on the stain) If the stain lightens and/or disappears it is algae.

Please pose a full set of test results ASAP.
Chlorine too high to be tested and chlorine high enough to kill algae are sometimes not the same. It depends on some of your other readings and how you are testing the chlorine. With some water testing setups (even professional ones) chlorine that is too high to test can be chlorine over 3ppm, which is not very high at all and often not high enough to stop an algae outbreak .