Spin-off of MOH's saying no

I actually asked my sister to be one of my maids of honor (I have two sisters) and she never basically said no.
I called her to see if she could get together to have lunch and I could ask her in person. She was rude and said 'I'm very busy I don't know when you expect me to find the time to have lunch with you. You'll have to come to my house if you want to talk.' I said it doesn't have to be this week, it could be next or the week after, whenever you are more free. She said 'I don't think you understand how busy I am'.
I called her again and said calmly 'how about we just talk on the phone then? Give me a call back when you can'. I didn't even get a call back, I got a text message saying 'YOU'RE NOT THAT BUSY. IF THIS IS THAT IMPORTANT YOU'LL MAKE THE TIME TO COME TO ME'. I honestly made an effort to ignore that she wasn't being nice because I just wanted the opportunity to ask her and not allow for things to go off on a tangent.
I then wrote her a nice email and said 'You're my sister, that's a special bond and I love you. Would you like to be my maid of honor?' She ignored my question and responded with craziness saying I never really made an effort to be in her life except when I wasn't as happy and I was single. Which is not true. She's been nutty in the past. In the past she would not call me back many times and then once when I didn't call her back I got a crazy message yelling at me and being really sarcastic on my machine. I played it for my fiance and he was like 'whoa...she sounds crazy.' I think a while ago I just decided it was best to keep my distance because she can act selfishly, manipulative (nice when she wants you on her side with family stuff and then turn on you and be crazy) and treat people badly. However, when it came time to choose a bridal party, I wanted to keep the door open by asking her and I still love her because she's my sister.
The last time I saw her at a family event we stayed away from eachother and then I went over to her and politely said goodbye and she didn't say goodbye back but said 'I GUESS WE'LL TALK ANOTHER TIME.' And again 'IF IT'S IMPORTANT ENOUGH TO YOU, YOU KNOW WHERE I AM'. Come on. I don't need that.
It makes me sad that the situation isn't ideal...I'm still going to send her invites to everything but I'm not sure if she'll show up to wedding events. I don't want to go crawling to her house and have her act like she's doing me a favor by talking to me. If she had accepted the honor, I don't think she would have been very giving, she might make things even more stressful. So even though the situation is sad, maybe this is better than if she had said yes.

take it as a blessing in disguise

but it def does su ck that she's being so childish about it.

I think you're heart is in the right place, but you really dodged a bullet. From your description of your relationship, it seems you have this unconditional love for her, but she is harboring some bitterness. I hope it gets better bt. you, but you're better off not having the tension around your wedding. There are so many things that can and will cause you stress, your BP should be a place of support and comfort, not addtional stress.

If she's this much of a PITA about this NOW....

Be SO GLAD she ain't gonna be your MOH, girl. End of story.

Pick someone awesome who doesn't come with BS-baggage. She's gotta be your right-hand-man so to speak so ... choose wisely.

Wow you guys are awesome. I love all of your responses! Touching and made me laugh.

I do have 2 MOH now: My other sister and my best friend. They are both very awesome, so I feel lucky.

Count your blessing. I have a sister and good friend like that, so you know I wouldn't ask them. For trying, but in the end you need people around you who are happy and not a downer.