Edith, whatever else we might know about her, had excellent taste in singers, and she acquired autographed pictures of them — whether in person or by mail.
In both cases (courtesy of eBay) I believe the signatures are genuine. I would vouch for Mildred’s because her calligraphy was distinctive, and Maxine’s elegant script was the same when she autographed a record for me in the very early Seventies. It is possible that Mildred signed her name to dozens of photographs and then wrote in the recipient’s name — the ink is slightly different — but that was common practice, I think.
So, Edith, thank you for being such a diligent and discerning fan!
May your happiness increase!