I don't know your Star Fling pattern. If you are starting with a 10-1/2" unfinished block,
it may be difficult to convert it easily to a 12-1/2" unfinished,
without getting into odd measurements to make it work.
That being said, it may work out perfectly.
You could draw your finished block out on graph paper.
If cutting individual pieces, be sure to allow for extra fabric for the seam allowances.
Or you could use the graph paper drawing as your PP pattern.