As a family of two adults traveling with a four-year-old child, I've already made reservations for the two adults through the Bernina Express website, utilizing the 'Eurail pass' reduction. Notably, I didn't reserve a seat for my child since the Bernina website clearly states that children under six travel for free.
Now should I make seat reservation for adults and child from Eurail website ? or if using Eurail pass is it mandatory that child needs reservation ?