So would be sorely lacking. Setting aside largely irrelevant types like Morgase/Sorilea who can barely even briefly rarely GRASP the Source, much less DO anything with it, many people too weak to be AS still have sufficient strength to actually USE the One Power. And any One Power strength scale omitting people who demonstrably HAVE such strength is incomplete and thus inadequate.
Perhaps she can; Traveling requires so much of the Power her inability to do THAT proves nothing either way. That we never see her even GRASP the Source on any other occasion is suggestive though. Aiel are very self-reliant, so she would be unlikely to use it for anything she could do as easily do physically, but other Wise Women channelers frequently used the One Power, while there are no instances where Sorilea was said to use it EVEN IN BATTLE. My guess is she ranks above Morgase (who does NOT?) but only by two or three levels at most.
When Rand is kidnapped she makes a little flame too ... and Cadsuane makes a comment in there somewhere that while she may be weak, she is skilled. I suspect she's the lowest level possible that still has some functioning ability with the Source. She's also got enough strength to be at least 100 years old (she has a great-great-grandson that is old enough to consider marriage