I don't know what to do with my friend?

[Doraa Weasleyy]

I would just ignore it and act like normal. If she really does like you, it will just be awkward and embarrassing for her if you confront her, and if she hasn't come out as anything, it could be very scary and traumatising.
It's not causing you any bother, and if you don't like her back then eventually she'll get over you (which is probably what she's trying to do if she's ignoring you) you just need to give her time.
And as for her dating other people? It's completely natural for someone to be attracted to more than one person, and have crushes on multiple people. Either that or she could be trying to move on from you. Either way, it's her business, and you should just leave her be.