Looking up Dr. Google for some shoes for my mum. She takes size EU 34 E (yep, tiny), Typed in "Size 34 shoes" but so many different widths to choose from I replaced "shoes" with E. Apparently "size 34 E" is a reasonable bra size. Got lots of pics or women modelling 34E bras. No shoes.
Unfortunately size EU 34 (UK 2 / US 4) ladies exist in the odd website/catalogue in that the size exists but in reality they don't. Mum hasn't had a pair of dress shoes since my wedding in 1974. She's worn kids shoes for casual wear since then but unfortunately her 1974 shoes have just fallen apart (too many weddings & funerals). There are kids dress-up EU 34 but they are frilly and/or sparkly and/or have cartoon characters on them.