The exact age of some superheroes has often gotten muddied, especially in recent live-action films, with some fans still unsure how old Tom Holland's Spider-Man was by the time Spider-Man: No Way Home happened. The same can be said for Miles Morales' Spider-Man and his love interest, Gwen Stacy's Spider-Woman, in Sony's animated films (Spider-Man: Into the Spider-Verse and Across the Spider-Verse).
While most fans love the romance building between them, the same couldn't be said for comic readers. In an attempt at preemptive synergy, Marvel Comics (very briefly) paired the two together.
However, because of the prospective age gap between the two, many felt uncomfortable with the pairing, but that's not an issue in the Spider-Verse films.
How Old Are the Spider-Verse Duo?
Miles Morales' age in Spider-Man: Into the Spider-Verse was never explicitly stated within the film, but fans did learn, through Gwen Stacy, that she's "older than [Miles]" by "fifteen months."
Shortly after its release, one of the directors, Peter Ramsey, seemed to suggest that Miles was a "13-year-old kid," but Ramsey may have only been referring to Miles' age in the comics, not the film.
Fast forward to Spider-Verse 2, and Miles told the audience that "for the last year and four months, [he has] been Brooklyn's one and only Spider-Man." However, he was also confirmed to be a sophomore at Brooklyn Visions Academy.
It's still plausible that Miles was 13 years old in Into the Spider-Verse and a freshman student at Visions if his birthday was between December and March.
So if he's a sophomore, Miles was, at minimum, 15 years old in Across the Spider-Verse, which also meant, at minimum, Gwen would be 16 years and three months old.
The Age Gap Between Gwen Stacy & Miles Morales
To give greater context to non-comic readers, at the end of 2016, shortly after Spider-Man: Into the Spider-Verse was announced, Marvel Comics unwisely decided to employ some classic, synergy by trying to pair Miles with the recently created Spider-Gwen.
For those unfamiliar, at the time, Gwen Stacy of Earth-65 was canonically 19 years old, while Miles was a month from being seventeen. In retrospect, it's not a huge age gap, but classic and casual readers couldn't shake off the fact that her Earth-616 counterpart was famously Peter Parker's love interest, so it still felt uncomfortable for many.
Suffice it to say, the relationship barely made it past their first kiss, and the two decided to remain friends. However, that didn't stop both Spider-Verse films from poking fun at this age gap, which was thankfully made smaller by at least nine months smaller.
Before Gwen returns to her universe at the end of Into the Spider-Verse, she tells Miles, "...I'm older than you. Fifteen months. But it's pretty significant if you ask me."
Another hung lampshade from the sequel was Rio Morales' comment to her husband about Gwen "[looking] old enough to vote."