Firstly it is a parents’ dream to walk their child down to the chupah. This is customary and obviously they walk down an isle to the Chupah. What else is there to walk down. And the isle should be long enough to have meaning to the parents. It is a very special and amazing moment. If you are NOT a parent that hasn’t experiences this Brocha you probably will not understand.
People have different minhagim. I was at a Chasuna in E”Y where the parents walked the Chasson to the outdoor chupa and the men followed and then the parents walked the Kallah and then the women followed. So there was no isle per se. When there is an outdoor Chupa, there might not be an isle either because there is no seating and people just stand around the sidewalk.
But that is the custom and if you choose not to follow that custom it is your choice at the time your child gets married. In addition, who are you to complain about the Kallah’s dress? The Kallah dresses like a queen on the day of her chasana. She will dress in the same tsnius manner that she dresses always. If she wears more cut out always she will carry that into her wedding dress as well. If she is extremely tznius it will show in her wedding dress as well. Everyone does according to their own standard and their own custom. It is foolish to have this discussion and have another go round picking on a Kallah this time.
Try to tell your Kallah, or your daughter not to dress up on the day of her chassanah. See how foolish you come off. Go ask your Rav if you are in the right? I have been to many chassidk weddings where the Kallah’s gown had everything on it except bells and whistles. To me it was too much, but to the Kallah she felt like a princess so kol hakovod, she is supposed to feel that way and no one should deny her that.