[user104658]

Now I don't want to bring you false hope because if she is really, fully telling you there's no way it's ever going to happen then you should listen to that. However.

#1 "I used to have a crush on you" is a lot of the time someone telling you they have a crush on you, in a "safe" way that sidesteps the fear of rejection.

#2 "I just see you as a little brother now" is 50/50 honestly it could be a flat out rejection, it could be (as weird as it is to say it lol) flirting.

Depends entirely on the vibe but if you can't read the vibe and you are interested you need to have a "no hold barred" conversation where you're honest about needing clarity.

I agree with people saying if you ultimately care MORE about the friendship and are only "having your curiosity nudged" by the idea of more then DO NOT go there as you most likely will ruin the friendship, because if you're just "curious", you're not actually all that interested. If however you now have genuine feelings for this person and think a relationship could work then I say it's worth finding out because frankly, the friendship is now under the shadow of that anyway, it's never going to be a purely platonic friendship. You need an answer either way.

Also don't listen to the bitter-boys trying to tell you that long-term relationships are "impossible these days/don't happen", almost everyone I'm friends with over the age of 30 is married or in a long-term relationship. It depends what circles you run in, I guess. People who have struggled to hold onto relationships will try to tell you that it's "simply not possible" but it's mainly to alleviate their own regrets and loneliness -- "it's not my fault, it's society!!" etc.