Availability of MultiSim on a Kids Sim plan

I’m reading conflicting information so I would like to double check here.

I would like to sign up for a Kids Sim plan, install that eSIM on a phone (which will remain at home), and buy a MultiSim option (for €5 per month) to install an eSIM in an Apple Watch for my child.

Can you please confirm whether the ability to add an extra SIM for €5 per month exists on the Kids Sim plan?

Thank you!