10 yr old kid, 6-7 knot unstable wind, stalling kite, kid hooked to 18m duotone juice and teacher holding behind, what are your thoughts?

Yes it was a paid lesson. For me it's a no brainer, but seems like some people has other opinions.

No, that's stupid.

But I guess the guy wanted the $$$.

Bigger kites don't fly much better than medium sized kites in terms of light wing fly ability. There is a minimum wind speed that an inflatable kite needs just to stay in the air due to it's mass. This us usually around 6 or 7 knots. Problem is with this little wind, the kite isn't likely to turn and climb back to zenith unless its an Aluula or SLS kite, or something more specialty like a Cloud kite or similar, especially if the rider starts moving downwind with the pull of the kite which decreases the apparent wind at the kite.

Light weight kiters don't advantage by massive kites. A light weight student (35kg) will have more than enough power from a 9m light weight kite provided it will stay in the air.

A light weight ram air kite can fly in as little as 4 knots but still is only really good for beach practice unless the kite if flown by someone who really knows what they're doing.

A quality lesson shouldn't happen until a minimum of 10 knots for water practice and 8 knots for beach practice. This way, the kite will fly reliably and the student will progress.

Dodgey lesson by the sound of it.

DM

Can only agree with the experienced Kite instructors above that their is more appropriate smaller lightweight foil kites or single strut lightweight inflatables kites in smaller sizes that are available to instruct with.
Really irresponsible trying to teach a 10year old with a 18m Juice in marginal winds.
What about a 3m Trainer foil kite.?
The instructor should really know better.

as we also know with kiting...ALWAYS RIG FOR THE LULLS.