Maggie Sottero Dress - Seam Allowance?

I cannot comment about seam allowance but if cleaning the dress was enough to tighten the fabric and it fit fine beforehand, I would not worry too much about letting out the dress because the fabric is apt to stretch again.

I worked in bridal for three years, and the boutique I worked at did sell Maggie.

I looked the Mylene Marie up, it's this one right? Generally, Maggie does leave a little seam allowance for alterations. However, because of the side panels under the arms, it could be different. I wouldn't worry too much, because since it fit when you bought it, it's likely to relax, but where exactly is the dress tight?

In that case, I would definitely check with your alterationist, but I really wouldn't worry too much. Since it does zip and button, and it was comfortable when you bought it, it's likely to relax, especially as the fabric warms up from your natural body heat, meaning the dress will become slightly looser as the day goes on. But, if it's something that's going to stress you out and bother you, absolutely see if you can get it let out. More stress is the last thing any bride needs! It's a beautiful dress, and I'm sure you're going to look gorgeous no matter what!

It also sounds like you're not far from the perfect fit, so hopefully letting it out a little will be no problem! 🤞