Member since 9/25/12
Date: 6/11/13 7:26 AM
Looking at it, there is already going to be some extra coverage on it. I make them for a woman 6X, so most of the time I add on to the skirt portion, increase the waistband half the waist size plus some and double the length of the ties.
Since even that was a clear as mud to me, my usual alterations are adding 4" (give or take, some aprons are already fairly big to provide coverage) to each side, add to the waist band half the measurement of the waist plus 4" (35" I believe is what I have it as) and then make the ties on a fold, so they are twice as long.
This one, you will also have to add to the ruffle. To get the amount you'd need, you'll have to walk the pattern skirt edge and the ruffle edge to get the ratio of gathering, and add the amount you added plus that extra.
The top looks to be the easiest to do on the sides and extend the curve for the front to make it match, which you'll probably have to redraw. Then add to that ruffle as well.
I am not sure what she considers average. I am a RTW 12-14 and can wear medium aprons like cobbler's that are supposed to be somewhat form fitting. One size fits all aprons tend to just need a little to the skirt, longer ties, depending on the bib, just a couple inches added for plus size.