That’s exactly the reason. It would have made more sense to “Alice” her up, so to speak. Instead of just saying, “well, she can’t age now, guys.” Put her in a moderately interesting and attractive outfit and have her have some enhanced speed and strength like Alice. There you go.
I mean, they did experiments to Alice in-between the first two films. We don’t know what they actually did to her? But trying to explain that the Nemesis infection slowed Jill’s aging after the R3make is just stupid. If anything, it would fucking mutate her. The Nemesis virus and G-Virus intensely alter the dna of the host on a massive scale—so much so that they eventually just become a blob. And you’re telling me that Jill just becomes an elf? Fuck off.
My recollection of that dogshit game is becoming foggier as time goes on, but I don’t see how giving her the cure (or whatever it was Carlos did) would suddenly leave her with that little perk, but none of the other nasty shit?