For most brides, wrangling a wedding dress in and out of the bathroom is a logistical difficulty. Sometimes the volume of fabric is a problem* (cathedral train?). Or maybe the lack of fabric is a problem (skin-tight sheath?).
Heck, I had a tea-length silk party dress, and I still was grateful to have my little sister to help me with it.
I've always assumed that helping the bride during a pit stop was the job of the maid of honor. (Unless she wasn't right there when needed, and then it falls to whatever attendant is around.)
But some attendants are squeamish -- and some brides are really private. So before you get to that night -- or that toilet stall -- ponder which woman you can comfortably tap.
Who's going to help you?
*Advice for brides with a train: Park head-in.