Victorian Style Hand-painted Flower Brooch

Vintage brooch, which also doubles as a pendant for your necklace chain is versatile as it is lovely. Sky blue background with flowers and a gradient fade-away scene. This art is bordered with a beautiful, aged antique gold looking filigree ribbon motif set for the base. There seems to appear to be an ink hand signature on the back with the woman's name Marge, in cursive writing. I have spotted an unidentifiable Hallmark stamp, I've shown in a photo. If you can help me identify this, I would appreciate it. I believe this is possibly from the '70s.