How can this be?

In 2 weeks you can possibly lose a couple more pounds. I wouldn't sweat it. At your final fitting if it is still too snug for your sister to zip it up herself you can ask if they can let it out a little. You should have an inch or so in the dress to let it out.

Depending on the shape of your dress, how easy it is to zip might also have to do with making sure it is sitting at exactly the right place on your torso. Daughter's dress always fit perfectly, but because it was an a-line style it was very fitted in the waist with a lot of boning in the bodice and a low back. Honestly, EVERY TIME I tried to zip her dress (she had it for a year, so she tried it on a lot), I had a terrible time and would constantly think what the heck happened???? But, every time they helped her put it on at the bridal salon (when it came in and at three or four alterations appointments), they zipped it right up without any issue. The problem was when daughter tried it on at home, we weren't getting the waist seam up quite high enough on her torso before I tried to zip it up. The bridal consultant showed me how to lift the dress up a little higher than it seemed like it should be, hook the hook at the top of the zipper, and then the zipper went right up, and, the dress "settled" on to her body exactly where it needed to be for the structure in the bodice to fit the way it needed to. Ask your consultant to watch your sister try to zip it and see if she can identify what's not working right.

It's going to be okay! You're still going to be a gorgeous bride. Keep up your hard work - you've still got time

You are going to look beautiful no matter what! Don't deprive yourself of water before the big day. I know someone who did and she passed out at the ceremony. Make sure you stay healthy and try not to stress (even though I know that is hard). As others said, there is always an inch or so for a dress to be let out if needed.

This happened to a friend of mine. She went to her final fitting and suddenly the dress didn't zip. She had not gained any weight, but the seamstress took it in too much.

Since your dress was snug, I am sure your seamstress didn't do anything to take it in. Anyway, my friend had to lose 15 lbs in order to get into that dress and she had 4 weeks to go. She was just in tears. A friend of hers put her on a low carb, high protein diet and increased her cardio. She was able to get it done and she looked stunning.

You can do this!!!