www.riversideparents.co.uk - we have 3 free soft-play sessions for kids three times a week at Downside Fisher centre on Druid Street. Details and times on the web site. If you go you can chat to lots of people who will tell you about more stuff in the area.
We go to riverside parents softplay and they have a special area for little babies to lie down and mums to sit. It's pretty good, I think your friend will enjoy it.
I myself would prefer to have more of an old fashioned coffee morning type thing. Soft-play is a little annonymus and we don't really get much of a chance to get to know other mums, because they are all focused in on or running after their babies.
Thanks so much everyone - I will pass the suggestions over. F33ona if you do set up a group please do put it up on the forum. The coffee mornings sound a great idea as another option and I think you are right about the conversation side of things.