Yes. Siblings attending the same class are eligible for 1/2 price registration. Children older than 1 yr must register (no charge for infants younger than that). See our pricing and discounts page.
Typically we can accommodate siblings 1 year younger than the stated age range, so 1 yr olds in Little Families Yoga (2-4 yrs) and 3 yr olds in Family Yoga (4-8 yrs).