I believe this yarn to be 4ply, no way it would knit to a normal fabric on 4mm needles.
Anyway.

co 12,
r1; k
r2; k
r3; k1, kfb, k8, kfb, k1 (14)
r4; k
k 20 ridges
k1, ssk, k8, k2tog, k1 (12)
k
k1, ssk, k6, k2tog, k1 (10)
k
k1, ssk, k4, k2tog, k1 (8)
k
k8, pick up 25 along side, pick up 8 from co, pick up 25, k4. pm for centre of round.
p1 round
k1 round
work 6 ridges, ending after a purl round.
k to centre front of toe (25 from back)
k3, ssk, turn
sl1, p6, p2tog, turn
sl1, k6, inc1, ssk, turn
sl1, p6 inc1, p2tog, turn
repeat last 2 rows once more (total of 12sts for short rows)
sl1, k10, ssk, turn,
sl1, p10, p2tog, turn,
repeat these 2 rows until only 42sts remain in total.
Sl1, k10, ssk, knit to back of foot.
K13, k2tog (closing gap) k to end.
* k2, yo, k2tog, * repeat to end. (10 eyelets ties)
K1 round.
P1 round.
Repeat these 2 rounds for 10ridges.
Picot cast off;
Cast off 2, * cast on 3, cast off 7, * repeat to end.