Anyone interested in very early 20thc genteel poverty, or indeed household economics etc in general might be interested in Virginia Nicholson's Among the Bohemians. Which is primarily, as the title suggests, about bohemian lifestyles in the early 20thc, but is actually very good on the economics and social norms that the bohemians were (in some cases, self-deludingly, reliant on family money, in some cases virtually starving in garrets) trying to break out of.
Domestic labour was astonishingly cheap pretty much up until WWI - not having a servant or two (given their cheapness and the lack as yet of labour saving devices for cooking, cleaning, laundry etc, ready meals etc) would be akin to not having access to a fridge today in indicating a level of poverty.
Plus I think we overestimate how few basic domestic skills certain classes of girl would have had, because they would have been expected to be directing servants, rather than needing to know how to launder or cook themselves. And with all meals needing to be cooked from scratch with no Nigella and Jamie-style 10-minute easy pasta options,, no labour-saving devices and few possibilities for refrigeration/freezing etc,
cooking and cleaning for a large family would have needed experience and training. Neither of which nice, useless Garnie has. Clearly she was brought up to 'better things'.
I'm always appalled by bluff old jolly hockey sticks Peaseblossom in The Painted Garden - as someone said, she was clearly the less fortunate or marriageable schoolfriend who comes to help out and never leaves because she has nowhere to go. But the bit that freaks me out is that when she wins the lottery (or saving bonds?) she spends it on funding the family's trip to the US, and shares a cabin with the children on the ship, while their parents are happily off by themselves on the other side of the liner, and submits to being extra hired help for the whiny American aunt the whole time.