I'm just (I hope) in the final throes of a novel set in the 1930s... Must be in the air.
The Gardiner is completely brilliant - weaves the personal and particular together with the largest historical and economic issues quite brlliantly.
I'm sure there are some 1930s memoirs but I'm having a blank - although there will be tons in the bibliography of the Gardiner. You could browse the "biographies" section of a big library and find some people of the right age to be children then. For some reason it's the childhood part of memoirs and biographies that seem to have the best social history built into them. I suppose once people grow up and start on whatever life meant they ended up writing a biography, it stops seeming like history to them.
Monica Dickens
One Pair of Hands - she got sick of being a deb and went to work as a cook-general (i.e. only servant) for a series of employers in the sort of income bracket you'd be looking at.
In fiction, - Elizabeth Bowen, my personal favourite E H Young, Rosamond Lehmann, (essentially, practically the entire Virago Modern Classics back catalogue
) Woolf of course, Vita Sackville West perhaps, Winifred Holtby,
<Added>The Beauman books is good, though she doesn't like E H Young very much, which is a grave error of taste