You meant 6c right? 6c seems to be her only antiair besides her dp. If they're at an angle or a range where 6c would get beaten, and you have the balls you can run under the jump in or roll under it. Otherwise I'd just block.
In a somewhat related topic, is it just me or does linne not have any mix up options while doing a blockstring? It seems to me that her approach is the trickiest mix up because she can roll or assault or emptyjump low/throw and if that's blocked all you can do is a combo into a relatively slow high hit(c charge c) or string some lows until they're far enough away to either disengage or attempt another mix up. in the corner you have 63214B which is pretty good but you need cs or meter to follow up. Am I missing something?