[Bear_in_RoseBear]

I couldn't see Hermione as Ginny's Maid of Honor.

Why not? It was Hermione after all who advised Ginny on how to relax around Harry, so that he could actually get to know her as more than just Ron's star-struck little sister.

You know, I was thinking about it this morning, and it seems to me that Ginny really set out to catch Harry, right from the start. For example, practicing her broom-flying so that she could try out for Quidditch... and have an excuse to be around Harry. Also, her involvement in the D.A. I imagine Ginny practicing her spell-casting in secret, determined to get good enough at it that Harry would notice her...

[Tanniker Smith]

Well, I could see it, but it'd be forced. Ginny's a year younger and always had her own friends that she hung around with. The main reason for it would be to have the three main characters together on the altar (with two of them making googley eyes behind the bride and groom's backs).

For Ron and Hermione's wedding, you have the three of them there regardless of maid of honor. OTOH, Hermione doesn't seem to have any other female friends other than Ginny and Luna.