Brown was the second best rider on Corkscrew in TDU and has proven herself to be pretty good on these kind of hills in LBL as well, so I don't think it was a certainty that she would struggle that much today. Especially not in a field that wasn't exactly the cream of the crop.
Climbs in LBL are longer and have steadier gradients - While today they had two ascents of Challember as opposed to the one steep climb in the two stages of the TDU.