I think I recall a Roy Yeates fruit & Veg stall either in or at the entrance to Brighton's open market. He was recorded as having lived in Newick Road (My Brighton website) and may have died in September 2006 (Argus memoriums Yeates & Yates).
I also see on FreeBMD that your Olga was an only child, and the Genes website has someone (perhaps you) giving Olga's birthplace as Littlehampton which is in the East Preston district not Steyning. So do you have a copy of the birth cert to sort that out, if not, perhaps you should get one.
Another curious thing is that there are two slightly earlier sequential Yeates births also in the East Preston area (1923 & 1925) but with a mother's maiden name of Cartwright. The son Ernest, born 1925, died soon after his birth, but another person on Genes is interested in the daughter born earlier.
Thinking there was some connection and Olga's mother may have been a second wife, I looked for the Yeates - Cartwright marriage, or the death in the area of a female Yeates of child bearing age between the years 1925-1927, but neither could not be found.
So presuming George and Violet were more than just partners, the other alternative was that there is a deadspot as far as the FreeBMD records are concerned, and in consequence, you need to have a closer inspection of the master index produced by the GRO.
Roy G