I am looking for a gym with a creche (preferably with a pool too). The only ones I can think of is The Nuffield Southside and The Harbour Club. The HC I think will be out of my price range ....though I am interested to hear if anyone has experiences of either or can recommend anywhere else.
Have you looked into Latchmere Leisure Centre? It has a great gym, pool and offers excellent on-site creche facilities called KidsFusion which I used a lot when I was on maternity leave (trying to get back into shape for the inevitable return to work!). Fees are very reasonable compared to some other gyms in the area. Hope this helps!