I'm going to ignore my alcoholic girlfriend when she is drunk
Why would you rather ignore your girlfriend?
I just want to act like myself and not have to talk to her when she's drunk.
If your partner gets drunk regularly, then you should talk to her when she's sober about her behavior. When she's drunk, though, you can't reason with her so it would be best to keep ignoring her or avoid being around her when she's like that.
But is it really worth my time to try to change her?
If you find your partner to be annoying when she is drunk than you should have a conversation to her about it when she is sober. It makes sense that being around drunk people can get annoying, however not spending the time to try and fix the situation could doom your relationship in the future.