Yes, also like adults. They must be able to present a visa when entering Turkey. As parents they should also have their own passport (so children are not credited in the passport of a parent), which will contain the visa.
es, a separate e-visa must be applied for for your child, even if it is included in the passport of one of the parents. Multiple visas can be applied for with one application form, in which case you must use the passport data of the parent who has the child in the passport for the child.