Quite a few Etsy shops do a nice job with vintage cards, including Vintage Recycling, where I found the sweet card shown here. Then all you need is a frame. I really adore the distressed handmade frames from Obrien Schridde for something a little special and befitting of the vintage card inside, but heck, you can even hit IKEA or a local thrift store or flea market if you have a good eye.
Alternately, you can frame a vintage hankie like the one here from Heirloom Linens with the word “mother” printed at top. The only drawback – when she’s all emotional after seeing the gift, she won’t be able to use it. –Liz
Search for vintage cards and handkerchiefs on Etsy to make your own custom present for Mom.