I have an OI made on forms copied to 90%. I also have a Petrel built to 95%. length on both is 17'. They both came out great for me, 5'7" and about 135 lbs. What is the width of the one you want to shrink and what is 10% of that? mine are around 19" width and feel tippy initially, but feel fine with practice. Just depends on what she wants and will feel comfortable in. You can adjust anything. There are pictures on the forum somewhere.