You seriously think the valleys doesn’t have mother and baby groups, child friendly cafes and baby swimming classes? Wow!
Do I think Abercarn is going to have less of these things than an urban area like London, Cardiff or Bristol?
Um, yes. Sorry.
These are basically glorified opportunities for new mums to meet other new mums, and you have to pay for them. Of course there are going to be less of these things in a small village out in the sticks, where there aren't as many people at the OP's stage of life, and of those there are, many of them don't have a lot of money and already know each other, so might well just be meeting each other for cups of tea in their own houses instead.
And where these things do exist, they will most likely be happening at a time when the OP, as the main breadwinner, is out at work in the nearest big town an hour's drive away. Assuming she is lucky enough to find a job.
Abercarn isn't the kind of place people move to. It's the kind of place people move away from. Like-minded people of the OP's age who grew in Abercarn will be living somewhere else now.
If they move to Cardiff she might have a hope of meeting other new mums her own age with professional jobs with whom she has something in common, or meeting like-minded work colleagues she can go for a drink with after work without needing to worry about driving back to Abercarn afterwards.
But actually living in Abercarn is likely to be incredibly isolating.