Hi Graham,
Found her I think:
Susanna Maria WHOLMES
GRO ref 1845 Dec Freebridge XIII 143
Also if you don't have her in 1861 census, this may be her:
1861 19 London Road, Kings Lynn RG9/1257 fol.142 p.2
Susanna WHOLME/WHOLMS (hard to read) servant 16 House servant born Nfk Gaywood
Hope this helps, Barbara