Our family tried snowshoeing for the first time today thanks to a Story County Conservation pop-up event at McFarland Park. They had $5 rentals for both kids and adults. The adults snowshoes fit great, but we struggled with the kid snowshoes, which kept falling off. I saw other families experiencing the same problem, so I wouldn't recommend renting kid snowshoes there.
I highly recommend checking out the trails at McFarland Park in the winter though. We really enjoyed our 2 mile loop which took us to the Skunk River. I also appreciate that they have restrooms available in the winter. The lake has been drained and the area around it is under construction but there are still plenty of available trails right now.