How long have the players in this group been playing? Have you been friends with them for longer than you have been playing Heroclix? Is this at a venue or at someones house? Is there other options to play around where you live? If these are people that you met through Heroclix and they have been playing awhile then it may be tough to teach them the right way to play. In which case if you can find another option to play at you may just need to suck it up and play their way.

Also it sounds like this group is confusing damage with damage dealt. Its hard to explain but they are two different things.

You may be right about her being the only one who does that to herself, but there are a few characters, like Darkseid and Invisible Jet, with the capacity to allow those they carry to be given non-free actions.

SoG Fire and Ice say hello