In my experience with DID people, there are both types of alters... those who only dealt with what happened THEN and those who also deal with what is happening NOW. For instance, if IRL some teenager is giving the DID person static or "lip" then the "teenager" inside would be the one to deal with it. (Perhaps what is called being triggered.)

There can easily be more than one adult, also, even if the reason for the DID was formed in childhood. Some alters don't age, others do. So one might have an adult who does the bookkeeping, another who makes the calls for information and social contact, and still another who goes to work!

Some alters have personal names, others take the names of their "job" and still others might not have any name in effort to stay safe or anonymous. And there are those alters who need to be protected, often "littles" who may not have experienced anything negative, but were protected by the creation of an alter.

Many child alters, while retaining many aspects of a typical child, can also have mature thinking or abilities that they" received " from an older alter. (Such as use of some words, being able to type, or color well.. etc.)