Tenforward

I email the museum to ask who it was! This was the response:

That’s Sandra O’Connell, who wrote the book An American Family During WWII. She actually works for Smithsonian and does signings somewhat frequently. She will be doing another signing toward the end of the month. We also currently have a couple of signed copies of her book.

Ok, this isn't totally helpful but I recently visited the Udvar-Hazy Air and Space museum in Chantilly outside of DC, specifically on June 18th, and there were some authors there signing books. One was Wolfgang Samuel and another lady whose book was about the families during the war. But I can't remember what her name or book was called! Some cursory googling didn't return anything but maybe your Google fu is better than mine!