A version of this article appears in print on Feb. 2, 2025, Section A, Page 3 of the New York edition with the headline: Here to Help; How to Travel With Babies and Toddlers.

Heidi Grevious has been teaching sign language to infants and toddlers, ages 6 months to 2 years old, at St. Vincent Healthcare quarterly for the past three years.

Now, their two children are 19 and 17 years old, and she's taken them to about 30 countries — many of which they've traveled back to multiple times.