Does it matter? God.
I find a few ladyboys hot. Some even looked cute enough so that if I saw them in real life I might fall in love with them. Also, I've met a few guys (like 3) that I considered sort of cute/attractive.
I'm neither gay or bi, though.
It's my personal belief that for everybody in the world, there's probably at least 1 person of the same gender they could fall for.
How old are you, btw? And it's not a good thing to fap to a friend's sibling, no matter what the sex.