I think the young lady standing may also be a Girl Gude. A senior Branch of Girl Guides was formed during the war. Although they could wear the same uniform as their younger sisters, rationing & shotages made it difficult for most to replace the uniforms that they had outgrown. They often just wore the triangular scarf & Guide hat with their school uniform (if they were still at school) or with their work clothes. The older lady, too, I think could be a member of the Guiding Movement. Her straw hat with the wide hat band is just like the alternative to the felt hat which was often worn in the summer.
If you Google " Leslie's Guiding History Site Time Line" & scroll down the page a bit, on the RHS you will see a guide in such a hat. I have no idea what position the lady would have held. I don't see a lanyard, so maybe not a Guider (leader), but perhaps a County Secretary or skills instructor??? A higher resolution scan, if available might give more detail of the hat badges.
Twilight