|Photo by A Boy Named Tsunami. Me and Punk.|
First of all, figure out what the problem is, if you can. Sometimes it's political views, maybe one of you is a vegan and the other is a life long worshipper of bacon. Who knows? Well, you should try and figure it out, because it might make it easier to relate to her if you know what the problem is. When there is a problem a relationship, it's usually a fifty fifty problem, and that means you have to be honest about exactly what it is you don't like about her. Could it be that you're jealous of her ability? Maybe you've made assumptions about her that aren't substantiated. Maybe she actively doesn't like you either, but that might be because you sent her your crappy vibes first. Be honest. I can't repeat that enough. And, if you're honest, you can admit that sometimes you just don't like someone at first sight. Is that an asshole thing to say? Maybe, but it happens.
If you hate someone, it's emotional. Guess what, emotions aren't always rational either. The question is, what is the emotional issue at the heart of the problem? Anger is just a covering emotion; it's safe to be angry or outraged, and it's too vulnerable to feel sad, or betrayed or weak. Is this person always rude to you? Is she truly bitchy for no reason? Maybe you feel hurt because of something she said or did, or maybe she's reacting to something you said or did. Look at your emotions, are they running you or you running them?
How do you cope? You have a couple of choices, and none of them are perfect, but they can keep you sane when you can't stand someone on your team.
You can just stick it in an emotional proof box and bury it in your brain. Yeah, it's not the healthiest of choices, but sometimes life doesn't let us have a resolution to every conflict. Sometimes you have to be the "Bigger man" and just let it go. If you keep nursing the grudge with your leaguemate, you're just feeding a downward spiral. Being emotionally detached keeps your emotions from boiling over.
Be polite and be professional. This is derby, not The Sisterhood of the Traveling Pants, so learn to make peace with people. They don't have to be your best friends, but you can be civil. Keep everything on the track professional and avoid spending down time with the person that annoys you. Don't make a giant production of it, just find something else to do. In other words, be a damned grown up. Don't gripe about the person to others in your league. It's just not good form and it will bite you on the ass eventually. Keep your dislike to yourself, no matter how tempting it is to talk it out with others. Now, this advice doesn't hold water if someone is threatening you, or harassing you. That is a completely different kettle of fish. That's a situation you need to take to your league rep, captain, or board members. Harassment is never ok, and a completely different matter.
Respect them for what they do on the track and in the league. Take the personal completely out of it. Hey, you may hate this teammate, but they have a killer hit to the outside, or hold a wall like nobody's business. Maybe she's really good at fundraising, or getting sponsors. Try to look at what they bring to the league. Maybe noticing her positive aspects will mitigate some of the hate you're feeling.
Keep the bigger picture in mind. Look, you both have the same goals (I'm assuming), and that's probably the best you can do for the future of the team. You want to be successful, yes? You want your team to kick all the ass, yes? Then let go of the petty and crap, cope with your hate and move on. Besides, you should be too busy training to have time to hate, but that's just my opinion.