Take heart OP, only a few days ago, I found myself in a similar position with a dear friend who is in the TWAW camp. I just couldn't get my head around how someone as intelligent as my friend, someone who is a researcher at that, knows so little about something other than to 'be kind' and to think solely on an individual basis. I did my best to explain why that approach does not work and that unfortunately, in this instance, it comes down to scientific fact that in humans, sex is not mutable and that being trans is an idea, a feeling, something that cannot be defined in a way male and female is, and that being born in the wrong body really is not a thing.
I have horrific chemo/menopause brain which just made the whole thing worse, as did the look on her face and pursed lips which made me feel like a huge bigot with everything I said. However, and on a plus note, she did admit that I had clearly done a lot of reading on the subject (this was when I was discussing DSDs are sexed), and that she had not. She also admitted to not knowing anything about APG, the fact over 92% of TiM retain their genitals, the contagion amongst autistic teenage girls, that puberty blockers aren't reversible and that male and female bodies, particularly once through puberty are very different things and male bodies, even on female hormones, will always retain a phyiscal advantage due to skeleton, muscles and the size of both the heart and lungs.
Although not convinced I'm not simply a raging transphobes, and at the very least, I think I have given her food for thought and she has promised to do some reading that isn't from people like Juliet Jacques. I have suggested Helen Joyce, Sonia Sodha and Kathleen Stock. She also conceded that TRAs are making things worse for transpeople. She also understand the different between sex and gender, and did agree that many conflating/confusing the two has gone a way to contribute to the belief that one can change their sex.
So don't give up hope. I doubt your colleague will say anything and if she does, your beliefs are protected by law. Not only that, you have scientific fact on your side. No debate is no longer a thing!