Could we have double bed frames for kids and teens ?

Are you saying you want double bed sized versions of those beds you pictured?
Cos with the way you worded it, it sounds like you're not aware that kids can already sleep in double beds.

Or are you asking for double beds, where a child (or teen) can sleep in the middle of the bed, as though it's a single bed, but with more sprawling room? (I doubt that would be added)

But more variations of double beds would be good. Every single bed should have a double version, and vice versa.