I too have this problem. Exactly as you have described. I find it particularly funny because it seems we both tried the halo marine method of fixing it. I even took a hill giant strength potion and tried to throw her to no success (not the throwing part, the talking part).

It seems my influence with her can only change in the camp too. If I talk to Shadowheart about Shar in camp, it lowers,but outside of camp, it does not. Unfortunate, because its the celebration night. I can't end the day because I'm trying to get my influence up to... well, we both know why I'm trying to get my Lae'zel approval up.

I really hope they fix it.