It shouldn't/hopefully it won't make a difference, but Cibulkova (along with Petra's next few opponents) and Stosur have completely different games (sorry Jan S).
As far as how slim she is: Its always hard to tell with pictures. But judging from her first two matches at Brisbane, it does appear that way. But we'll just have to wait and see (and also wait to see if it makes any difference in her play)?
She could do herself well for the Aussie Open, if she made the finals or won it here.