I don't recall the 90s cartoon or the reboot explicitly calling out the character ages.
The original 5 X-Men (Angel, Beast, Cyclops, Iceman, Marvel Girl/Jean Grey) were explicitly high-schoolers (15-18) when introduced in 1963. They have since gone on to age at incredibly indistinct and unclear rates. In that 60's series, they are depicted as students at a co-ed boarding school.
At the '75 revival (also where Wolverine is introduced and would have met Jean Grey), there is an unclear amount of time since the last book in the original run. However, cyclops is flying an SR-71 Blackbird, and no one is acting like it is because he is a child prodigy. They then return to the school, but the whole 'high-school students' cover is mostly ignored (certainly few, if any, 'original-5 acting like teenagers' storylines) until new teenage characters are introduced.
By the time the 90s cartoon was produced, Jean Grey has died, been resurrected, taught some of those other teen mutants (at the school, or others like the New Mutants and the like while she was part of the X-Factor split), had kids in alternate timelines, and a clone of her had married Cyclops and had a kid (she would also marry Cyclops in the comics in the middle of the cartoon's run). None of that clearly indicates an age, nor directly contradicts her being 17 in the cartoon (which, as I said to my knowledge never stated an age). However, they were consistently treating her as someone vaguely in the young-adult range (honestly anywhere from 18-39).
There have been character age-squickiness (and squickiness in general) in Marvel, to be sure. Rogue and Kitty Pryde, in particular, had their age and adulthood lurch about haphazardly; making depictions of their romantic encounters/affections/sexual energy directed their way really unsettling. Some of that is because 1) Rogue was a character salvaged from the cancelled 70's Ms. Marvel series, so some of her early depictions were never depicted*, meaning the audience only saw a young daughter of a villain who lightheartedly battled ROM and Dazzler before switching sides before getting thrown into some pretty heavy psycho-sexual stuff** and then a will-they-won't-they with a clearly adult-coded Gambit; and 2) with Kitty Pryde there seems like there was an actual internal miscommunication about how old she was supposed to be, with her being stated as 13, but other places her being treated as a high-schooler. Also, she originally had a 'young-teen's crush on older teen' thing towards Colossus, to which he was clueless (or pretended to be to avoid the situation). Later writers missed the memo that it was supposed to not be a thing, and made it a thing.
*including her battle with, and absorption of powers and memories from, Carol Danvers
**In the original Genosha storyline, Wolverine and Rogue were teleported to the mutant-apartheid state (naked, because that's how the teleporter's powers worked, naturally). A powerless Rogue had 'some liberties taken' by some of the guards until Danvers emerged as a split-personality taking over to keep her functional while Rogue's main personality shut down. It hit hard.
So yeah, the comics aren't great about age-appropriateness. However, Wolverine in particular has* actually been incredibly good about these things. He's often been paired up with a single female teammate (Jubilee, Kitty, Psylocke, Rogue, Storm, X-23) for sidequests, but always been all-business and gruff-gentlemanly (/fatherly for the young ones). A few other times (and in varying continuities), he's been depicted as having rather unromantic physical situationships with at-the-time very adult-coded Domino or Storm or someone; but most of the time he either gets involved with Asian women who are destined to die before the mini-series' end, or (unfullfilledly) Jean Grey (who again, is usually depicted as some level of fully adult when it happens). More often then not, he's the resident chaste hero -- the one you attach to for your baddassitude and gruff-masculinity needs before switching to Gambit or the like for your gets-the-girl sensations.
*stipulation: I've barely read an X-Men comics in 30 years.
