I’d be OK with paying for it. Even at a level of most of the other contenders.
Unless…
It forms part of a ‘New Plus’ option - now there’s an idea 
Monzo has already done pre-paid (which is essentially what most ‘child’ accounts are) and so the architecture must be there. And to wrap it into a ‘New Plus’ option could work for many customers.
Not worth me paying for an account for my youngest. I just put it in an interesting pot and withdraw it to main when he wants to buy something
He thinks it’s cool that he has his own Monzo pot, although the 1p interest he’s earned this month isn’t filling him with joy 
The same service provided for free already? So yes why not?
No
I thought nimble cost £2.50 a month?
At the end of the day pocket money accounts produce little to no profit. Tiny deposits = tiny interest, no overdrafts, no loans, fewer transactions. Without a monthly fee/ additional charges it wouldn’t really be a business.
If the incremental cost to provide the service is next to nothing, as it would be for a digital bank, but the opportunity would be a new customer for life then I’d say that’s a good investment.
does not equal free.
Next to nothing * 10000 = something… 
How old would you think this was a good idea? My sons are 10 and 8…
Probably down to your level of trust and circumstances with each child.
In my case, my Daughter was to start High School in September 2019 and would be travelling on the bus to school each morning, then back on the bus in the afternoon.
I felt like a source of cash for emergencies was necessary and so got a goHenry card way before High School started to see how she reacted to it. She loved it - and used it very carefully too during the summer hols - which impressed me. So we kept it going and this is how she receives her weekly spending money. She now hates spending on the card and likes watching the balance increase each week. Financial education? - Job done.
The one I have for my daughter doesn’t. I paid something like £12 for the year.
Perhaps someone knows how to use their website? It might say on there?
[edit] well, I looked on their website so you don’t have to. The charge is now £2.49 a month or £28 a year.
I wouldn’t pay that for the service they give. I only went with them a couple of years ago because £12pa was fair.
This is the key here, and I am surprised it is not on the short term roadmap.
Monzo has no problem with growth right now - but it WILL slow down at some point (if it has not already). By implementing this, it will be adding trickle growth in years to come by becoming the first proper bank account an adult has. For this reason, it should be free and be thought of as part of the marketing budget.
Couldn’t agree more. My legacy bank account is still the one basic one I opened when I was 18. I’ve had other bank accounts since, obviously, but it’s always done the job!