From the pattern webpage:

Keep your little piggies as warm as bacon with these cute and cheery Mary-Jane slippers. They will add a bounce to your step, reminiscent of spring lambs, and the flowers will remind you of the happy spring flowers hiding under the snow. Suddenly, it just feels like spring…

Finished Size:
Slipper measures approximately 23cm (9 inches) along bottom from toe to heel (unstretched).

Notes:

• Slipper is worked from the toe to heel in circular and regular crochet.
• If you want a longer or shorter slipper, adjust the pattern between the rows 14-23 or 26-51.