At a bar/restaurant. In London. Fairly swanky place. I'm not sure if a dress might be too much, so maybe trousers/top combo? I keep seeing women in those ankle-length black trousers and patent high courts - is that still a good look? 
Please help - I will be in the company of a gaggle of smart stylish women for the first time in quite a while. Not sure my usual SAHM gear will cut it. 