I'd have to go hunt for it though.
Also we say Graendal cut off and shield Aran'gar with no angreal to help her. Which goes toward skill and dexterity playing some role in this dynamic. I don't know that males can "smother" the females as easy as that either. Skilled channelers have been shown to fight off shielding attempts. Graendal rebounded Verin's circle, given there were angreal involved as well as linking that seems to come down to ability not really strength.
Shielding just seems like one of those abilities that some have great skill with and others do not ... Look at Asmodean, he had months to break Lanfears shield and could not do it. Even Moghedien could unknot a shield that was tied off in moments.
I think Graendal just stood there and let the shield bounce off. It was an absurd attempt by Verin who couldn't even sense how much saidar she was facing. It's actually kind of atrocious that this circle did as well against Graendal as all the Light's strongest women did against Hesselam. Who wrote this stuff!
But yet shielding is a Talent and it might be as potent at Healing. It was strange that Asmodean couldn't unravel his shield because Moghedien said that any of the Forsaken could have unravelled her shield on Liandrin. There are many possibilities but we'll never know.
Fan of Lanfear