Looks like we have a new book claiming the spot of first Courtney Whitmore Star Spangled Kid later called Stargirl. She is mentioned on the cover, this predates Stars and Stripes #0. I count 4 whole panels one is repeated, one page of back story in the secret files format, and a high school yearbook that gives us some background into characters taking place in Courtney’s story + a panel of Courtney not uniformed. Some are claiming the book is scarce in their eBay listings I haven’t ran the numbers myself.
It’s enough for me to call it first appearance and a full one too.