Hi! Knowing someone who has come out of the closet ( whichever closet actually ) can really shake things up for a person. I know the impact my coming out had on a number of close friends... All of a sudden, here's someone you've known for a good while I assume, revealing something so core about themselves that will likely have a huge impact on the rest of their life. It's such a profound and bold thing to discover and explore. It's bound to stir things up in you that were locked away.
Exactly that happened to some friends of mine. One suggested they were gay ( still in the closet ), one came out as bi, and another came out as transgender.
Something else to consider. From my limited view point, like-minded or similar people seems to always congregate together and make social circles. A long time ago before I came out, an inordinate amount of my friends found themselves somewhere on the LGBTIQ radar

. They're all still friends with me too, even after I transitioned.
Having said all of that, there is not a soul on the earth who can tell you if you are or aren't transgender. But a gender therapist can be worth their weight in gold, and help you to figure it out. If this is something that stays with you and needs answering, I highly recommend finding one. Until then, you've all the time in the world to really just be, and/or explore as much as you're comfortable doing. Perhaps even talk to your friend about it. I'm certain they would be understanding.
xx