Is it not good and justified storytelling to have Diana be unknown about the outside world and forced to stay despite wanting to see more because that's who she is?
Diana isn't Clark, she frankly should be around those conflicts if it helps her learn to be an established leader archetype. She should and almost actively does use Themyscira as an example of a better world.
Again, Diana is an immortal, 30 some years would be a blink and you'll miss it moment for her.
If you're going with the well of souls thing with Mala, maybe make Diana actually around her age... 17 and 20 is questionable kind of. I really don't see how the Well needs to influence this either. Part of the Well's cool factor is that it hasen't been active since Diana was/Nubia came out, kind of a big thing in that story. I assumed they meant long time as hundreds if not thousands of years.
And not all of those need to be in the present.