This is a bit of a strange blog.
It follows the same initial tack as @viques post of 22.15 - to distract from the issue at hand by bringing up tragic, but irrelevant circumstances. It is horrific that SP experienced abuse and hate for a disability but it does not follow that because you have experienced hatred yourself that you are incapable of being hateful.
She then appears to imply that this tweet was 'stupid' (she earlier asserts she did not tweet this herself but supports it). I don't really follow why she would continue to support what she describes as a stupid tweet. Why not just say she doesn't support it?
She then goes on to assert that there are a number of reasons a person might be hateful, which is of course perfectly true. But the law doesn't (usually) preoccupy itself with the reasons someone might come to be hateful - it has to to deal with the facts, and concern itself with harm caused to others, regardless of the individual history and psychology of perpetrators. It should act as a deterrent to others when it judges a communication has gone beyond freedom of expression to become a hate crime.
So all in all, it sounds like does recognise that the tweet was problematic, but stands by the right to post problematic tweets. Everyone has got their line, but for me I would not be keen to invite someone who maintained their right to support such a tweet on such an occasion to speak at a university.
I believe she has the intelligence and insight to recognise that tweet has real potential to endorse and encourage people with transphobic views and that she should disavow it, but she does not, and persists in her support for it.