I don't recall anything like that in the only definitive film version of the book that I care to recognize, shot in 1959, with James Mason and Pat Boone.
Of course, they did include a female character played by Arlene Dahl in the expedition, which was a diversion from the original.
If you're going to go criticize adaptations, you could at least identify which adaptation you mean, you know!
Kid in Journey to the Center of the Earth.
In remake in 2008 there was a 13 year old.
I am glad you overlooked that remake which along with
the Time Machine remake tried to ruin two of my favorite childhood memory favorite movies.
Sorry I wasn’t specific and you are right I shouldn’t criticize adaptations as I did.
The casting of Pat Boone (like Frankie Avalon in Voyage to the Bottom of the Sea) was to appeal to teenage fans. Does that make us feel old? Yes.