What is the definitive guide to free winter activities for families in Chicago according to Mommy Poppins?

Based on the available content, Mommy Poppins has a guide to family-friendly winter activities in Chicago, many of which are completely free. The guide is designed to help families make the most of the city's coldest months. Unfortunately, the specific activities included in the guide aren't mentioned in the content I have.

Would you like to know about winter activities for kids in New York City as suggested by Mommy Poppins? Or perhaps you're interested in other types of family-friendly activities recommended by Mommy Poppins?