Could this be the family you are looking for
1851 - Brilley
William Price 47 farm labourer, born Trewerne, Radnorshire
Mary 40, Brilley
Mary 13, Huntington, Herefordshire
Harriet 8, Brilley
**Fanny 6, Brilley
Lucy 6, Brilley
James 7months, Brilley
Frances/Fanny is not with the family on the 1861. They are now living in Huntington, while Frances is a servant in Hergests.
The marriage certificate would confirm (or not) the name of her father - or maybe someone could do a parish look-up for the marriage in Huntington (Huntington is in the Presteigne registration dist.)
Hope this helps.