John, some have interpreted Gluesis's message in this way but most agree with OP and think that Gluesis is apologising in a diplomatic way for GZ's behaviour whilst not openly betraying her. To me, saying "I'm sorry you feel hurt" is not the same as saying "I'm sorry I hurt you", it takes any of the responsibility away from the apologiser and puts it onto the apologee.
Personally I think GS couldn't care less about the ins and outs of GZ's behaviour (especially since she doesn't even know Tidy well) and is just trying to find a solution to the problem she's probably been hearing about for weeks that will stop her from having to choke her own sister on a pritt stick.
tidy, I think you're doing the right thing, but I'd be going nuts thinking of all the things I wanted to say to them. To relieve your feelings, PLEASE anonymously post GZ a sylvanian figurine as suggested by someone upthread. GZ is bound to write something about it on FB!