Sure, from the outside perspective it's really skeevy because the writers did the whole "she's a young girl with a childhood crush" thing first, and then changed it in a rather arbitrary and unconvincing fashion. And I certainly understand regarding it as a creepy and unfortunate storyline. But from within the story, the explanation behind it covers all the objections and is presumably plausible, given Hal accepted it. And I find storylines and characters that differ significantly from conventional standards to be the most interesting - a plot line revolving around the debatable legitimacy of artificial personality traits is more interesting than one in which the whole thing is dismissed out of hand with "she's drawn young-looking so we're going to treat her as a human child without further thought". It's part of why I find Captain Marvel such an interesting character - he regularly undergoes a transformation that explicitly changes who he is mentally, which raises all sorts of interesting questions.
But yeah, the actual storyline as written was kinda lacking in the interesting parts, and seemed more focused on some sort of wish-fulfilment on the part of the author. Though I did see an analysis that suggested that it was intended to a "appearances don't matter as much as what you are inside" special message kind of thing, in which case it was just handled somewhat poorly - if she was meant to have been an adult all along, who merely appeared young to humans, then the backstory of Hal rejecting her due to her not being mature enough doesn't fit, and nor does the idea of her mind having been aged-up along with her body.
Thanks for reminder.
