Coworker of mine ended up getting the promotion to the department…

Coworker of mine ended up getting the promotion to the department lead when she's been here for significantly less time than me. I wish I knew why. A part of me wants to think maybe it's because I'm a trans gal, or maybe it's because I'm autistic, but perhaps they truly did think she's a better fit for the position than me? I have no way of knowing which one of those it is, if there really was any malice against me for who I am or if it's just a business decision.