Think I've got her now - just using Jane in both 1891 and 1901.
That Birth entry you mentioned in Southwark St Saviour seems correct, albeit late 1888, it matches her age on the census OK.
Let me know if you want it transcribed ?
1901 - RG13; Piece: 409; Folio: 107; Page: 15 : Father William a Cab Washer born Plymouth
1891 - RG12; Piece: 348; Folio 126; Page 45 : Father William a Horse Keeper born Cornwall, and a brother George born late 1890 (

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