EWTN Catholic Q&A
Apologetics or History
Question from Noah Parker on 04-20-2017:

How old were the 12 disciples when they were walking with Jesus. I have been hearing that they would have been teenagers.

Answer by Richard Geraghty on 04-24-2017:

Dear Noah,

The Apostles were grown men. St. Peter married. They fished for a living. Mathew was a money changer. The were not teenagers.

Dr. Geraghty