Maybe a bit odd..but I think she has some intimacy issues.. And she is using tango to get over that.... Be that as it may, it strikes me as odd that someone would take a class in partner dancing, tango no less, who does not want to be touched.
I've heard people who have had psychological mishaps in the past that has turned them off closeness, and use partner dancing as a rehabilitation tool.
She is making progress. At the beginning of class she was way way apart...now at least she is ok with a very open embrace...an embrace nonetheless... I and other leads can work with that.
I do not expect all followers to allow me, or any lead, to get into a close embrace - by far the majority do however