C. Hedley-Charlton, illustrator of this postcard, is something of a mystery to Wikipedia, and other areas of the web. She’s a she, and she was in the Artist’s Suffrage League, which printed and published the card sometime around or after 1907. The League, led by the Arts and Crafts artist and glazier, Mary Lowndes, designed and produced banners carried by Suffragettes in organized marches and rallies before the First World War.
I thought at first it said ‘Votes for Nannies’, but looking at it more closely it's probably ‘Mammies’. The card, which is rather grubby, has no message on the back.
It would be described in the postcard trade, rather movingly, as ‘unsent.’