Just wanted to follow up on this thread. Sorry it's taken a while, but I've been having quite a dialogue with cousins.
So as far as my family is concerned, we're not connected with Bryn Derw. I have however been exchanging emails with someone who does have a connection. He has a Margaret Roberts in his family who married a Robert Jones and his Roberts family were the one at Bryn Derw. One of the differences we identified that his Margaret Roberts was born around 1829, whilst my family's Margaret was born around 1825-1826.
Let me know if you would like more information.
Regards, Gordon