Is it normal for a friend to suddenly have a crush on you?

Hello readers,

By the way, I am a female and so is my friend.
I was with her and we were playing truth or dare and I was dared to run around in my bra, which I did because it was truth or dare, duh(!). When I came back to the real world, I went to grab my top and she snatched it, telling me she’d only give it back if I let her stick a tennis ball down my bra. I swiftly said no and tried to snatch back my top, still in my bra. After chasing round after her, I managed to get it back and put it on but I was slightly dishevelled. I walked away and when we said goodbye I tried to act normal, and I don’t think she realised I was hurt and confused by her actions.

Looking back, I realise she has always been obsessed with my bra and has frequently told me to take it off (as a dare or in a jokey way). And earlier this week she told me I was beautiful, which was unusual for her as she is normally a frequent swearer and is more likely to call me a f*cking b*tch. Earlier this afternoon she also admired my bottom, saying it was curvy and beautiful.

Now, I wonder if she may have an abnormal crush/obsession with me and possibly has an inner lesbian side. By the way I am not a lesbian.

Is this normal?