Go for it. If she rejects you for outer esthetics, she’s a bit shallow. You never know what will happen unless you try. It could be hard but I think you should go for it. Sit her down and tell her. Just because you identify as straight doesn’t mean you can’t fall for your female best friend. Sexuality is fluid. I hope everything goes well. Keep up your chin sweetie.
"We’d been having a sort of tacit conversation about it for a couple years. Then one day, his sister, who already knew, was teasing him about having a crush on a boy at school. And I heard him say: ‘Well, maybe it’s true!’ So I said: ‘Son, we’ve never really talked about this. Are you gay?’ And even though he was 6’4”, he came over to me, curled up in my lap and just sobbed and sobbed. It was one of the most beautiful moments of my life, actually.”