Oh, I'm not very good at all with the 'how to deal with people' side of things - but I can tell you what I would do.
I would try, I think, to talk to her about it - tell her that you miss spending time with her, and that you feel sad that your friendship and time together has fallen by the wayside a little bit. What I wouldn't do is confront her about doing things her fiance's way, because that will probably make her defensive and she might withdraw from you. If you find it hard to speak about it, perhaps write a letter and give her it - though admittedly that will seem odd if she doesn't know you're Autistic. Make sure she knows that you understand why this has happened, and that you understand that organising a wedding is time consuming and stressful. I think that the most obvious overtone of whatever you say should be that you cherish your friendship with her.
That's the only thing I can think of, other than keeping quiet and hoping she comes around after the wedding.
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"I'd go further - I'd say 'Life is wasted on . . . people.'"
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