W.F.A.S. meaning?

Hi folks, I photographed a headstone in Sheffield the other day with the following inscription:

In
loving memory of
Harriett Dawson,
(W.F.A.S.)
the beloved wife of
George Edward Dawson,
who died July 4th 1918, aged 50 years.​

Has anyone come across the acronym W.F.A.S. before, and if so what does it refer to? A Google search hasn't offered anything relevant. Given the date I thought it might be related to the First World War, but it might also be something local to the Sheffield area, or something else entirely.

It's not terribly important but I'd be grateful if anyone could satisfy my curiosity!

 

I have found "Women's First Aid ..." in newspapers in Yorkshire around 1916,
and "...Section" was used later. So that looks likely, but it's not quite what I thought at first. There were a number of similar volunteer groups, with Section replaced by "Nursing Yeomanry" (the best known) , "Corps" (in Scotland), and I suspect others.

 

Thanks Stuart! I'd tried a number of searches for Women's First Aid/Field Ambulance Service/Society etc. but couldn't find anything specific.

Another source has suggested Woodseats Friends’ Adult School and I'm now thinking that might be it.