Narishma is in his early 20s. 23 y.o. IRRC, he's learner and not a sparker, though, so his age would be a bit irrelevant.
Taim told Rand Narishma had the Spark... but you are correct he is only about 20

LoC
Letters
"Somebody who learns too fast?" Rand broke in, and Taim flashed that half-smile again.
"No, not one of the Forsaken in disguise, not unless he’s managed to disguise himself as a boy not much past twenty. His name is Jahar Narishma, and he has the spark, though it has not come out yet. Men usually show later than women. You should return to the school; you would be surprised by the changes."
Domani Drag Queen in the White Tower ... Aran'gar watch out!
Is there anyone who *doesn't* think Galad can channel?
05/06/2010 02:36:20 AM
- 1625 Views
It is just describing what a person goes through in a heightened sensory mode. He can't channel. *NM*
05/06/2010 02:49:39 AM
- 432 Views
Re: Is there anyone who *doesn't* think Galad can channel?
05/06/2010 03:17:56 AM
- 965 Views
He cannot. This passage is similar to one in New Spring
05/06/2010 03:36:19 AM
- 754 Views
uh, me. and thousands of others. it's called the void, which tam can do. *NM*
05/06/2010 07:09:52 AM
- 320 Views
Wait?? Tam must have some channeling genes since Rand is his son.... *NM*
05/06/2010 06:21:40 PM
- 318 Views
On the fence
05/06/2010 12:44:45 PM
- 712 Views
Re: On the fence
05/06/2010 11:22:52 PM
- 657 Views
Re: On the fence
06/06/2010 03:27:06 AM
- 634 Views
Re: On the fence
06/06/2010 02:22:35 AM
- 677 Views
Re: On the fence
06/06/2010 03:27:54 AM
- 528 Views
They still see channelers as Dark Friends.
10/06/2010 03:51:44 PM
- 715 Views
More likely they'd do what the Seanchan would when/if Tuon Channels
13/06/2010 12:21:12 PM
- 728 Views
As you pointed out
13/06/2010 02:08:34 PM
- 719 Views
Only for the short term
13/06/2010 02:48:54 PM
- 732 Views
Perhaps. Perhaps not. Nothing is completely static.
13/06/2010 05:41:59 PM
- 849 Views
right, cause in a few months they are going to change more tahn 1000 years of doctrine *NM*
13/06/2010 10:32:56 PM
- 377 Views
Yes. Exactly. In three days two Aiel clans ended a blood feud.
14/06/2010 03:14:42 AM
- 853 Views
None of these situations is really the same
14/06/2010 03:18:59 PM
- 750 Views
Re: None of these situations is really the same
14/06/2010 03:38:42 PM
- 717 Views
I think you are overstating the situations below
14/06/2010 06:02:12 PM
- 687 Views
Nonesense. The Sul'Dam hadn't started channeling.
14/06/2010 07:26:12 PM
- 777 Views
The sul'dam who have realized what they are know it's just a matter of time
14/06/2010 07:50:52 PM
- 813 Views
As sul'Dam they need to be taught to channel.
14/06/2010 10:38:33 PM
- 682 Views
hello, Seta and Bethamin took the leap on their own. sul'dam are right at the edge
15/06/2010 01:48:25 AM
- 1251 Views