As far as I know, there is no age restriction for tutoring in LingQ. You can read an old answer to the forum I linked below, and there is no mentioning of it in the tutor FAQ.
I copy/paste the same answer to your other thread, there’s no need to open double threads, active users usually read every title.
Give a bit of time to the team support and they will answer you, if not, send them an email.
Here are your researches:
Previous answer from the customer service:
Knowledge base for tutoring:
FAQ for tutoring:
This line is added just to make the answer not identical for the bot. 