Like iwashere85 said, the slow replies are probably due to the title - actually, there are two votes to delete this so I'd strongly suggest not titling any future eHelps like this again. It would be terrible if it were deleted even though it is a perfectly valid eHelp. I'm going to tackle this point by point, but forgive me if I don't really know what to say at times. Religion is not something I'm strong on.
First off, we cannot and will not ever be able to find out what happens 'afterwards'. I am so sorry to hear about your sister - if it helps, I had an aunt who was probably the most charitable, kind person on earth who committed suicide, and who knows where she is now? - but just remember that while you still remember her, she is not truly gone. It will be hard, and there is no shame in your questions. Grieve for now, but there will be a time when you must stop grieving her death and move on to celebrate her life. I'm not sure what to say regarding where she could be. Only God knows. For now, just pray for her. I'm being delicate about this, seeing as religion will never be something I can counsel about. However, I don't see why you can't address our pastor about it. I assure you, it is not selfish at all! You are perfectly justified in talking about it. You say you are struggling with God - well, what better way to puzzle things out than with the leader of your church? We are often tested and trialled in life, and sometimes you just need help and guidance, no matter how selfish you may be feeling.
As I said before, religion is not a strong point of mine. What I say next is merely my own take on things - who knows what's correct and what's not?
We all go through periods of doubt and denial. I'm not going to push you in any direction - where you go, religion wise, is entirely your choice - but just remember that God will always welcome you back. There is no need to feel like your problems are too trivial to ask for help. God hears even the smallest voice.
Of course God has a plan, but in my opinion, it is not unchangeable. Remember that God has no power over freewill and your sister chose her path. Also remember that God alone judges accordingly - I don't believe that just because someone chose the path of suicide, it means that they are automatically condemned. So was Andree's suicide part of a plan? I don't know, you don't know, no one knows. But comfort yourself with the knowledge that God is fair and merciful - the most you can do is pray for her salvation and honour the life she lived, rather than despair over her death.
Again, no Support Leader is a trained professional and you should DEFINITELY consider my/anyone else's advice before taking it, especially on a contentious topic like religion. I stress again that this is what I've been taught and what I think. If it doesn't suit you then there is absolutely no need for you to listen to anything I've said. Religion is different for everyone - I am also a Catholic and you are evidently a protestant, so there will be differences. However, if you do want to continue talking then feel free to PM me and I will try to help.
I'm sorry for your loss,
- Scui