My records have suffered some disorganisation, following hardware failure of my old computer. I have two extracts from the 1901 census for Daniel Greening in Pontlottyn:
14 Greenfield Street, aged 52. This is my mother's great uncle. His wife is shown as Elsie Greening (no maiden name given). This does not sound like Susan. Among his children living with him (4 of them), the 3'rd is Laura. There is a possibility that this may be the ones, but it is a long shot. This Daniel was born in "Wolton Edge" (more likely Wooton under Edge) in Glos.
5 Picton Street, aged 23, married to Laura Ann, aged 19. No children listed. He may be the other Daniel's son.
The older Daniel had at least one brother, so he may have had nephews named after him.
My brother has more information about the Greening family. I will ask him.
Your Daniel does not sound like either of these. However, it is likely that there may have been other Daniel Greenings in Pontlottyn. Both the Daniels I have records for were railway men (listed as "Railway engine coaler" and "Railway engine stoker" respectively).
I feel that it is probable that, however many Daniel Greenings there were (or still are) living in Pontlottyn, they were all related to each other.
My researches have stalled, due to pressure of other things. However, your message has stimulated me to re-start. It sounds as though we are probably distantly related, but as yet I do not know how.