Meeting up with a couple of friends soon in central London. We're coming from out of London / London suburbs in opposite directions so really needs to be central so no-one is travelling too far. It'll be a weekday and we'll have a 4 year old, a two year old and a 1 year old. Where can we go (indoors) where we can sit and have a natter whilst they play? Are there any play cafes / soft plays / toddler groups in central London that might fit the brief? I realise it might be a tall order 