If the weather is fine, there are three playgrounds in town to enjoy, the one at Lake Daylesford is fenced & the one in the Mineral Springs Reserve in Hepburn is quite good for littlies.
Lots of shops in the main street & big indoor market called the Mill Market that has an indoor cafe as well, good if it's raining.
The Hepburn Bathhouse & Spa is a beautiful indoor heated 'pool' / relaxation area which you can take little ones for a swim. Bit pricey to get in, about $25?? but kids aren't charged & it's for a couple of hours so good option if the weather is a bit crappy. Take your bathers!
Have a great weekend!