Hot take: i never understood the whole controversy around him dating an alien with a very short lifespan.
She isnt a child in their society, just a (young) woman. Had she remained with the okampa she would likely have had romantic partners around that same time in her life, possibly children as well. For that matter, as far as I know neelix isn’t interested in her for her age in any way either, so I have a hard time seeing how it is considered creepy or inappropriate. Also, the actress was a normal adult woman, so that wasn’t weird either (I cringe more at the scenes of O’Brien and teen aged Keiko in that one TNG episode, at least they didnt kiss I guess).
I found him more annoying for his petty jealousy and overused mister vulcan interactions (although I generally enjoyed their dynamic).
She was the equivalent of 18 for about a month or so? in her life cycle. She was probably older (and more mature) than neelix by the point she broke up with him.