world war one nurses male and female

[Guest makeshift]

I am trying to find more info on my husbands aunt and Uncle during the great war.

There is a photo of the Aunt Elizabeth Mannouch in what I assume to be a nurses uniform and another of the man Walter Hobbs in Army uniform there are two badges on his left sleeve the lower one is a round badge with a cross in it the one above is also round but seems to have some sort of pattern on it which look like black and white squares

There is a upside down chevron on the sleeve as well. He is not wearing a cap

Walter and Elizabeth were married in 1915 and worked together in The Caterham Mental Hospital (no dates as yet) so I am assuming that Walter was possible a medical orderly during WW1 Where would I find further infomation on him and his war service Many Thanks