I've seen a lot of knit/crochet bag patterns call for an I-cord for a handle. Perhaps that would work?
You could sew a fabric handle much like you would for a sewn/fabric bag (vs. knit or crochet) - cut a looooong rectangle and fold it in on itself twice (use an iron to press it nice and crisp and flat) and stitch around the outer edge. That might be a bit more work than you want, though.
When I made a felted crochet bag I just used single crochet stitches and chained as long as I wanted the handle and then did 2-3 rows. So like a sideways scarf, which you could do either in knit or crochet to create a handle. For knitting, cast on however many stitches long you want the handle to be and work only a few rows (in the stitch pattern that matches the bag or just garter if you wanted) until you achieve the width of the purse handle you want.
Good luck with future purses and bags -- yours is absolutely lovely!