In 1881 Ann/Elizabeths 2 siblings John & George in the household of a George Donkin & Isabella (nee' Jennings. Interesting census ref RG11 5035 63 4
Are you aware of another 3 Donkin/Straker births other than those known.
Finally are you convinced that William Donkin Ann's father was born in York, I must admit i'm not for various reasons.