Adding a picot hem or something else?

I am making this sweater for my daughter.

http://www.ravelry.com/patterns/library/ballerina-top

It has a garter stitch edge (5 rows) On my swatch the edge still curled. can I add or change the border edge to be a picot hem? I would hate to put the time in this sweater and then the edge not lay right. Are there other options? A knitted on border maybe?

Have you tried knitting the sweater to see if the edge stills curls? I wouldn’t add a picot edge as with the edging around the neckline it would be too much. If you try knitting the sweater and it still curls then I would suggest a knitted border with a lacy opening effect.