I know that we currently have adolescents in the game, but I was wondering if we will be able to create them directly from the character creator?
Yes once their height are adjusted. 
I really hope we can create zois of any age/age group in caz.
That means babies, toddlers, and adolescents.
You can customise the look of the young adult, then change the age group, and when they age they would have the looks you want them to have. This already works with children aging to adolescent and beyond.
Because I want to create a teenager, I might not want them at the beginning of the life stage, I might want them at 10days out of 15 which the stage lasts by default.
There’s some work to be done regarding this for sure.
I agree, that would be really cool to be able to select where they are within the life stage. That way you could create a few different zois of the same age (like 3 children) but select who is older, etc OR make them twins of the same age.