No. 6 Store dress Size 0

I’ve had this dress for years and sadly cannot wear anymore since the waist is slightly too small after having 3 kids… 100% silk Perfect condition The “waist” more fits me on the upper ribcage, about 3” above my belly button. I have a 26” waist but measure about 27.5” where the tightest part of the dress fits me. This part of dress is 12.5” or so across