I don't mind the second image of Claire but I prefer the image of Claire in the car over the one of her in the bedroom. Even though the images takes you outside, I think it would be acceptable since you're doing a diptych which can imply compare and contrast.
Katie is great. Both really strong images and they work by themselves, too.
Regarding images that work singularly: I think the second image of Andrea as well as the image of Claire in the car would both work by themselves because of the symbols and gestures. The others are too still but they function as portraits wonderfully.
I love the childhood diptychs. I appreciate Michael's portrait a lot now as opposed to the way you had a diptych of him earlier--its an easier read. And I can read enough into the symbols to understand what you're trying to say with the portraits.
My ONLY issue with Noel is that you cut off his hand!!
I like "Girl World: Try Me" and "Girl World: Head." The text is great because it insists on a literal interpretation by the audience. Maybe it's the sequencing but "Girl World: Pin-up" and "Girl World: Double Fisting," causes me to think they are unfinished.
I think making images of your grandmother is a good idea. If I were you, I'd make some more portraits. I'm not sure if I would jump into the portraits with Melanie et al because I don't think you'd want to start rolling then have to stop since you're leaving.