When I was making Christmas presents for her cousins, my younger daughter thought they were terrific, and wanted me to make her some too. I wriggled out of this nicely - all nieces wear children's sizes, and my 13 year old daughter is in adult sizes.
However, the little sun-top Simplicity 9652 was not too hard to alter.
I made the child's size 14 a little longer (perhaps a tad too much), and added a FBA to the child shaped bodice to fit a more grown up figure. I used a different variation of the top, with an angled front and non-adjustable straps, and wrapped it up with the the straps pinned in place. If I had actually fitted it to her whilst making it, the only change would be to use slightly longer elastic for the gathered front neckline. I don't think it is bad enough for unpicking. (Post Christmas laziness is rife here at the moment)
The top is made from quilting cotton, upper bodice lined with batiste. It is very cool to wear due to the open back and loose empire line shape.
My daughter also benefited from a knitting disappointment. The first bolero I made for my 10 year old niece was far too big. It fits my daughter nicely, so I was able to give it to her instead. She is very pleased with it, and was surprised with her gift, which is a bit tricky when you sew and knit in the family room!