Do I need to make decaf kombucha for the dcs?

[Mere]

I'm trying to get my kids into kombucha, with a particular hope that it will curb ds1's sugar cravings.

1. Should I worry about caffeine? My kids are young...
2. Am I correct in thinking that if I do a shorter first ferment, the kombucha will be more sugary? I'm thinking that might be a good way to get ds1 to like it initially.

TIA!