Back to the mother Lilian Rowena Gatrall - she was with the Hollis family in 1901 as adopted daughter, spelt Gatrill.
Mentioned by Tazzie
Lily Gattrell age 15 with the Hollis family as adopted child in 1911 - Fanny has a granddaughter her birth
HOLLIS, LILY ROWENA -
GRO Reference: 1915 D Quarter in PORTSMOUTH Volume 02B Page 709
Added think this is her death
Lily Rowena Cuthbert age 77 Birth 6 Dec 1915
Registration Nov 1993 Isle of Wight
Edit -
Apologies Nell you had already posted about this Lily I missed it

I agree with you there must be a link somewhere of course she may be the daughter of Violet and named after Lily Rowena Gatrall - the only way to find that out would be to obtain her birth certificate an instant digital image is available
1939 there is a E M Hollis born 1932 with Lily Cuthbert (Lily R Hollis married Sep 1939 I. Wight)
No mmn (not given her full name as not investigated further)
HOLLIS, E M -
GRO Reference: 1932 J Quarter in ISLE OF WIGHT Volume 02B Page 956 Occasional Copy: A
Looks as if she married as Cuthbert E M, Jun 1957 Hampstead