Hello Caz, well much of what Valda says is what I have been thinking. I too found William and Ann Herbert in Queen Street Cheltenham 1871 and again, I think in 1881 with further children. However, if Clara was first born, followed by two boys 1866 and 1868, then why was Clara shunted off to live with their Aunts?? At one stage I thought that Clara might just have been visiting on the day of the 1871 census, but this is not the case because she seems to be living with them up to 1901 and probably by 1903 where I think I found her death.
It seems so strange to give the first born child (of a legal marriage) away to family to bring up, doesn't it?
There is also the senario that Ann just took William's surname without ever marrying, that used to happen then and all children were legally registered by both parents under Herbert surname.
With Cornelius, as I mentioned a few messages back, Charlotte (or someone) may have come clean in order for his marriage details, or fictitious to save face at time of marriage. Was the Charlotte witness to marriage Senior or Junior. If by Charlotte junior suspect this might be a true father name, if Mother was dead at time of marriage and no further embarrassment to her.
As there seems to be no sons produced by Charlotte Senior and you suspect incest, then perhaps an Uncle or Cousin were involved!!!
One could keep going.
Tiffy