They do look older to me, but Razz has a point: no one mentions them aging, and there's no explanation as to how they would have aged if that crystal was holding them in stasis.
That said, since their ages aren't mentioned in the games at all, just hinted at, everyone can have their own idea and we all have the same chance at being right. Just as an example, I think 12 is a little too young, so in my version of the timeline, they're 14 at the start of ANB, and 17-18 in DotD, whether they physically aged or not.
Of course there is one thing that hurts the theory that they did age somehow: Cynder's choker and bracelets still fit her perfectly.
That's because Chris and Mike decided to suddenly add those iron jewelry back on her, telling us that Cynder was facing her fears of being Malefor's pawn. Still, they should've added the scene where Cynder puts the jewelry back on her, but they didn't have time.