We also stopped at Daisy's Milkbar in Petersham for a Knickerbocker Glory and the best Bacon & Egg roll I've ever had (I've had a lot). We thoroughly recommend it. It is a great old school Milkbar with yummo food and friendly staff.
The morning session was Button Art. The kids had to draw a picture of something they liked then use water colours to paint the background. They each got a bowl to fill up with the buttons they'd picked.
The age group was 4-10 years, some were local primary school kids and some were home schoolers. It was a really nice mix.
Here's some of their stuff