The pop up party would consist of:
50 minute Busy Bees session in the venue of your choosing 
Your choice of theme from the selection 
Tuff tray play 
(Messy play or dry explorative play)
A birthday photo backdrop to get those lovely photos to cherish. 
Suitable for up to 15 babies/young toddlers.
Please note older children can take part ,helping the younger children. They usually enjoy this.
The above can be adopted to suit the event and location.