Thought Capel was probably from Marriage Certificate
There is no area Capel in the Talgarth area.
If she was declaring Birth in Capel Hamlet she is referring to Capel as us locals called it
Meaning Capel y Ffyn up in the wilds of Llanthony Valley on the Welsh side of Offa's Dyke on the narrow C class Road
Hay on Wye to Pandy on the A465 Hereford to Abergavenny Road the route Miner Walter would have taken to migrate to Brynmawr .
Capel is now about 1 hr away and 20 miles from Talgarth via Car now via Hay on Wye where we lived 1988 to 2016
Would never use shorter AA planner route of 13 miles unless I was on Horseback which I have been many a time at Tregoyd and would have been her only means of Transport then.
BBC2 Gardener Monty Don has his Farm at The Vision Farm at Capel
"Not alot of people know that !"
If Hannah was born and lived at Capel she would not have had her Birth Registered in Brecknock but Rather
Hereford Herefordshire or more likely Abergavenny Monmouthshire.
You also need to look on 1841 1851 Census in those areas.
Her Father not having work for her on the Farm in the wilds of Capel in her Teens
Would probably have sent her into Service 1849 ish in the Talgarth area that had some Rich Families and Big Houses in that area
the Vaughans and the Powells
It would have been uncommon for the Master to get the Servant pregnant
She would leave the household and go into local lodgings.
Then her Mother would meet someone prepared to take them both on as his own though not legally.
Which 1851 Census District 1,2,3 or 4 in Talgarth is she on ? And what address or Head?
Don't understand the RGO refs.
https://en.m.wikipedia.org/wiki/Capel-y-ffin