The purse for my MIL is done! Here is the picture of the finished object.

And now my MIL can take a 32 oz. square Nalgene bottle with her wherever she goes! It just happened that this bottle was a perfect candidate for blocking the bag as it dried.

Someone had asked for the pattern, so here is what I did.
I really like the look of Sophie from Magknits. I started with that pattern, and made some modifications.
Yarn: coned wool, probably DK weight. MC = dark pink, A=light pink, B=seafoam green. I am guessing that I used about 100g of MC, 50g A, 50g B.
Needles: #6 and #8 Boyes Aluminum interchangeable circular
Notions: stitch markers, 3 stitch holders, and a button or bead for closure
First, I mapped out the pattern I wanted. I knew I had 3 colors to work with, and I wanted hearts. I made this chart for the colorwork. The grid paper was easy, I just made an Excel spreadsheet and made the columns and rows equal, then printed it with gridlines to have a blank sheet to work with. My pattern will work with any chart that is an 8-stitch, 7-row repeat.

With a #8 needle, CO 39 stitches in MC, with yarn doubled for extra strength (note that you should use #6 needles here to have a clean, square bottom). K 28 rows in stockinette stitch.
Pick up and K 13 sts along the left edge of the rectangle just worked. Pick up and K 39 stitches along the CO edge. Pick up and K 13 sts along remaining side. (104 stitches)
pm. K 4 rows in MC.
K 42 rows in chart, beginning with the row that has color B (first MC row in my picture is superfluous).
K 4 rows in MC.
BO 46, place 6 on holder. BO 46, place 3 on dpn, remaining 3 on holder. Make an I-cord with the 3 stitches on the dpn until the cord is 20 inches long. Place stitches on holder. Make a second I-cord with the last 3 stitches until it is also 20 inches long. Twist the cords together and join with the 6 stitches on the opposite side using kitchener stitch.
Using crochet stitch, make a loop that will serve as the closure.
Felt and dry. Add the button or bead where the closure loop will reach and stay taut.