Hi jofeb04 - I'm sure there are some other south wales mums here ... have you looked through the Meetups threads? Mumsnet tends to be quiet at weekends, so don't be discouraged by the lack of replies X
I'm in Wales too.
I'm 36 married with DS twins 6yo and a step DD 10yo.
I've lived in Cardiff for 18 years but I'm originally from the valleys, in fact your very near my old home town of Ystrad Mynach.(If you can call it a town).
My parents still live there and my DS's are off there this afternoon to stay for a few days, to help cover school hols.DH will have them at the end of the week, but I'm working right up till Christmas. I work in the Dental Hospital in Heath.