There are 60 stitches on the needles of the large size sock and 54 for the small size. The good news is that we're going to knit the heel flap on the next 30 stitches for both sizes.
K2 with main colour yarn. Pick up contrasting yarn and move it to the front of the work. P2 with contrasting yarn and move the yarn to the back of work. Continue K2, P2 pattern until 30 stitches have been worked, ending with K2.
To make the knitting easier to handle, divide the rest of the stitches evenly between the 2nd and 3rd needles.
Turn the work. The heel flap is worked back and forth on the 30 stitches on the first needle. P2 with main colour yarn. K2 with contrasting yarn, wrapping the yarns around each other to avoid a hole. Remember to keep all the floats on the wrong side of the work.
Alternate both rows until 24 rows have been worked for the large size OR 20 for the small size. Be sure to work the first stitch of each row. Don't slip them. Break the contrasting colour yarn , leaving about 10 inches to weave in later and continue knitting with the main colour yarn.
Now, for the heel cup:
Row 1: K19 stitches, SSK, Turn
Row 2: SL 1 purlwise, P9, P2Tog, Turn.
Row 3: SL1 purlwise, K9, SSK, Turn.
Repeat Rows 2 and 3 until all the stitches have been worked.
Pick up 23 (19 for the small size) stitches from the edge of the heel flap, knit across the instep stitches and pick up 24 (20 for the small size) stitches from the other edge of the heel flap. Knit 5 of the heel stitches and slip the remaining 6 stitches onto the first needle. All rounds begin at the centre of the heel now.
Rnd 1: Knit to last 3 stitches of first needle. K2Tog, K1. Knit across instep stitches (needle 2). On third needle, K1, SSK, knit to end of round.
Rnd 2: Knit
Repeat these 2 rounds until 15 stitches remain on needles 1 and 3 (for both sizes).
We're back to 60 stitches for the large size and 54 stitches for the small. There's not much left to do now. Check back on Thursday and we'll finish then. Let's do something different tomorrow. Too much of the same thing tires Grandma Coco right out.