Her age would be augmented to a small degree given her tiny ability, especially since WOs lead harsher lives than an AS would ... and given that Bair, who cannot Channel is equally ancient in description, yet clearly younger than Sorilea I think it's safe to say that Sorilea has some bonus longevity.
Her brief description of her Tower "training" indicates ITS brevity: Stating it took hours of frustration just to grasp the Source ONCE strongly suggests that was the ONLY time she EVER grasped it, and the LAST the Tower ever bothered with even perfunctory "training." Since the AS knew her ceiling the moment they saw here (so precise reports of it probably arrived before she did) they also knew she could never be even an accidental threat to anyone even if she managed to grasp the Source every time, which she almost certainly would not: They did their due diligence, such as it was, for diplomacys sake, then sent her on her way. Her time there was more about learning the Towers way than the Powers.
As for outward physical signs, Sorilea does not look YOUNG, just no older than somewhat younger Bair, and the books do note Morgase retaining her youth more than one would expect, so that difference is also negligible.
The main difference is that, though channeling was not a primary WO concern, Sorilea almost certainly got FAR more channeler training than Morgase, simply because it was practically impossible to get LESS. She probably got more "training" and "practice" trying to wave a kerchief throughout ONE AFTERNOON than in the whole REST OF HER LIFE COMBINED. The mere fact Sorilea can grasp the Source at will shows more training than that; it does NOT necessarily show more strength.
Obviously Sorilea has more training. But she's also clearly stronger than Morgase. The books make it clear that Morgase is the weakest possible female, that her ability is so tiny as to essentially be non-existent. The sheer amount of times it's mentioned makes this crystal clear that she is so weak as to be surprising, much like Sharina is so strong as to make AS nervous around her. Sorilea OTH is merely noted as weak. It's simply stated that she wouldn't have been raised Accepted and left alone. She then exhibits ability to actually use the OP
Cadsuane even suspects (incorrectly) that Sorilea could be close to her own age (295), something she wouldn't consider if Sorilea wasn't at least strong enough to have a fair amount of slowing. Yes Morgase has also slowed, but she looks perhaps 10 younger than she should rather than a more powerful woman who would look Nynaeve's age at 100 years.
