In a note relevant to Morgase's story, RJ said that below level 57, the ability to lift anything with the power (lifting stuff is a factor of comparison he used) drops to a feather. Morgase is at minimum 57, maybe a few levels above. She's very likely comparable to Sorilea. The difference is that Morgase doesn't have a personality that surrender control easily (like Nynaeve) and it would have been very hard for her to learn to grasp the source no matter what. As it was, her strength is way below the cut-off for the shawl, and even that to make Accepted. The AS awoke her ability for political motives, and I doubt they put that much effort into it when it was clear Morgase struggled. Sorilea, on the other hand, was taught as much as she could, and could perfectly embrace the Source at will and learn difficult weaves that she couldn't even make work. The WO understood that very weak women may not be able to channel much, but they still could pass on all their OP knowledge to their future pupils... I doubt the WO have lost weaves nearly as often as the WT did...
I don't understand why people think that Morgase could be anything higher than the very lowest level of channeler.
LOC (Prologue) - Fifty times trying to sense the True Source to find it once, and when found, twenty times attempting to open herself up to saidar in order to catch a dribble once.
Morgase is someone who can only sense the source 2% of the times she tries. The one time we saw her channel she was nearly overcome just making a scarf flicker in the wind. I cannot imagine how anyone could be weaker than this. Surely Morgase is a 66! Unless she is higher and the lower levels are reserved for people who sometimes "sense something", but what would the point be of those levels? Or unless she underestimated her own strength, but then the sul'dam thought she was negligible, and basically not even a channeler.
Sorilea is a functional channeler. She can embrace saidar at will, and do very small things. She's not even comparable to Morgase IMHO.
