Well, don't pursue her. Not a good idea. So you can either distance yourself, or continue like nothing's changed. It's up to you, whatever you feel is necessary.
Keep your feelings out of the way for now. If your crush has a boyfriend at the moment , and your crush isn't a polyamerous person, forget about pursuing them in the romantic way. In the chance your crush breaks up with their boyfriend then you can think of telling them. Don't tell them while they are in a relationship, it will most likely end bad for both parties.
Avoiding her a bad option- if you care about her, then you should be there for her, and staying friends means that if she does break up with her boyfriend, you're in a good position to tell her how you feel.
Telling her COULD make her look at you in a different way, and see you as an 'option', but I doubt she'll suddenly just dump her boyfriend for you. Either she'll feel uncomfortable around you, or she'll empathise and you're friendship will carry on as normal. There isn't really much to gain from telling her now.
Not telling her in the other hand maintains your friendship, shows her you care about her and keeps you close to her. Just try and improve the bond between you.