I think the local paper would be a good source of information - hope for a report of her funeral, or an obituary? The local archive service would be able to tell you which paper to try, and where copies are held. I think it's unlikely that the relevant dates will yet be available on the new digitised service, so it's either visiting the archive or the British Library or getting someone to do it for you.
If there's no central record of her OBE then there is a possibility that she didn't get one and there's a mistake somewhere - clearly a mistake that the CWGC accepted for their database? The OBE was normally awarded to relatively well-placed people; working class and "other ranks" would not normally receive it at the time, so again I have some doubts. As a very long shot, you could try asking the CWGC what their source was for the OBE information.
I think I've found her indexed as Louie Holme in Bournemouth in 1911; in 1901 with two sisters and her parents in Langdale - her father a wood carter and waggoner.
