Do children, 'once they become celebrities in their tender years; does it not steal the 'care free' that's the essence of childhood years?
There are actual case studies on this subject, many made decades ago.
I recall watching a documentary on child stars, Shirley Temple was one focused subject. It was a rather old documentary.
Ignoring the current subject models, there are a few things which must be considered when evaluating the impact of fame on a childhood.
1. Most importantly is the driving force behind this need for fame. Is it the child's idea or someone elses?
2. Is there a balance in the child's life? Does the drive for fame outweigh the drive for play?
Is it the child's idea or someone elses?
While it is important for a parent to guide their child but when the reason for a path is for the parent's benefit over the child's, it will affect the child's development in negative ways.
In any assessment of this nature the most important factor is
The Reason For...
Does the drive for fame outweigh the drive for play?
Children and young adults (teens) need unscripted experiences to build healthy relationships. Regardless of the driving entity, Mistakes must be made for the child to learn. Surprises must happen for the child to know how to deal with the unexpected.
History is full of mentally unbalanced individuals who were famous as children. It is also full of well-balanced people who were also famous as children.
The road to fame often requires a sacrifice. Fame tends to change people (no matter the age) but fame is a temporay social condition.
How important is your primary school spelling bee award when you are 40 years old?
How many people actively watch and adore Shirley Temple?
Do you think Albert Einstein, Alan Turing or Stephen Hawking started out to be famous or became famous later in life? Do you think their parents specifically partnered to reproduce and create super-intelligent offspring?
A way to measure the condition is to remove the child from the environment. If the child still functions as a child, chances are the path to fame is being handle effectively but if the child can't cope with being a child, something is wrong.