I don't think Anna can win, here. She was stitched up by the Guardian, who have behaved incredibly badly. It may be that Anna enjoyed the date and identifies as a lesbian despite being open to relationships with transwomen (although many others would then disagree with her about the definition of "lesbian"). It may be that Anna felt entirely uncomfortable with being set up with an opposite-sex date.
Of course Anna has now tweeted about it herself - so that's the final word on this, right? Well, no. She's not a free agent, here. It may be that she is being utterly truthful about how she feels in her tweets, and sees no difference between dating a tranwoman and dating another actual lesbian. But she is also aware, as we all are (whatever our opinions) that to express discomfort or anger at being set up with an opposite-sex date would be to be destroyed online, sent death threats and rape threats, may well be ostracised from her real-life friendship circles, whatever. She's not tweeting in a vacuum.
So, this isn't just about Anna, and her reaction to this event. It's about the Guardian putting one young woman in an impossible position without her consent. Even if Anna is truly, genuinely, totally fine with how it all panned out, that doesn't absolve the Guardian for their homophobic, disrespectful, dangerous fuckwittery.