mb4u70,
Welcome to the forum, we are glad you found us and sorry that you need to. You will find this is a good place to vent and get some "school of hard knocks" advice from people who have already been in your situation.
Let me summarize my understanding of the situation. Your younger sister is a meth addict. Addicted sister (AS) was in prison for something and was released about 5 years ago. AS lives with your Mom; they are about 3 hours away from you. AS was doing well (not using) for a long time but now has started to use again. AS went to a rehab but was kicked out due to using. AS is chronically verbally abusive to your Mom when she is using which is now all of the time. AS has an outstanding warrant out for her arrest; Mom will not call in a tip to LE as to where to find AS.
"I feel like a pretty big evil-witch older sister right now but I can't stand seeing my mom hurt like this and my sister continues to make bad choices and not show a lot of remorse or care for those she's hurting."
I think you should concern yourself only with the well being of your Mom and not your sister - I know this is very easy to say and very difficult to actually do. The truth of the matter is that you and your Mom have no control over the behavior of your AS - meth has control over her - you are correct -- she does not care who she hurts or what she does as long as she has the meth -- that is how addiction works.
The question becomes what to do? First, protect Mom. Whether that is getting a protection order or calling in and tipping off the police where to find your sister becomes your and /or Mom's choice.
As others have already suggested, you need to find some help / support for yourself and your Mom - Nar-Anon, Al-Anon, CoDa and CR are all peer support groups that will offer you support -- look for meetings in your local area and give them a try. They have restored many of us to sanity and taught us all that when it comes to addiction - you did not Cause it, you cannot Control it, and you cannot Cure it.
This is the story of a couple in my Nar-Anon home group; I offer it to you to maybe provide a glimmer of hope.
A couple in their early 70's have 3 adult sons. Two sons live in different parts of the country and only see Mom & Dad a few times a year generally when they come to visit the grand kids.
One son is a heroin addict and for whatever reason lived at home with Mom & Dad. Early 30's, typical story -- can't seem to hold a job for long, not married. About 3 years ago as the son's addiction got deeper and deeper he started stealing anything which was not nailed down from Mom & Dad's house and selling it to finance his ever growing heroin addiction - cash, jewelry, electronics, he even sold their snow blower!
As his addiction deepened he became more and more verbally abusive -- laying the guilt trip on Mom & Dad -- addicts are generally very talented in this activity.
Then one night their son became physically violent against his Dad. Mom mentioned this incident to one of the other sons in a telephone conversation. She did not anticipate what that son would do -- he called local police who showed up at the house one night and arrested the addicted son for elder abuse / assault.
Son ended up in jail for some period of time and then was released on probation - Mom & Dad did not know where he was for about 18 months they were worried sick -- since their son is an adult, his probation officer would only confirm that he was alive - no other info. Mom finally tracked him down and then stalked him at his work place and met him in the parking lot one day as he came out of work -- he told them he was not ready to talk yet. Mom & Dad respected that decision but made sure that he had their phone numbers, etc.
Eventually son called and they started having lunch or dinner together and getting to know each other again. They now have a relationship again - not terribly close but not combative or resentful either.
Son is several years clean, holds a full time job, lives in an Oxford House and manages several other Oxford Houses in the county, is active in NA and with another organization which attempts to educate the public about addiction.
Mom & Dad are very proud of their son and his recovery. They ALL believe that if he had not been arrested and sent to jail, he never would have found his sobriety and might be dead by now.
The moral of this story is that jail is not necessarily the end of the world for an addict -- it might be the beginning of a new life.
Keep coming back,
Jim