Answered by Shaykh Yusuf Weltch
Question: Is it permissible for a woman to travel accompanied by her young son?
Answer: In the Name of Allah, the Most Merciful and Compassionate
Conditions of a Chaperone
It is permissible for you to travel with your 12-year-old son. A woman must travel either with her spouse or non-marriageable kin (mahram) who is trustworthy, mature (i.e. reached puberty), and of sound intellect. The pre-pubescent child is allowed as well, like the mature. [al-Hadiyah al-Alaiyah]
The Age of a Pre-Pubescent Child
A male child is considered pre-pubescent (murahiq) when he reaches 12 years of age. This is because 12 is the earliest age that a boy can reach puberty. [al-Hadiyah al-Alaiyah]
Hope this helps
Allahu A’alam
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani