My wife is trying to trace her paternal grandmother, and it is testing

A GRO search of her name bought up a couple of probables, one of which has no mother's maiden name.

Any ideas why?

I'm intrigued, because family rumour has it that she was born in a workhouse in Birmingham, and no one knows her mmn. I understand that some workhouse records are kept at Birmingham library, but can only be accessed by a visit.

Elsie Smith
DOB 07/02/1899
Married - 13/03/1921 St. Pauls. Lozells, Birmingham
Spouse - William Newey
Father - William Smith - Silver polisher. Deceased by 1921

The GRO that I found :

Elsie Smith yob 1899 M Q Kings Norton Vol. 06C Page. 525


Steve.