I am making the Snow Girl sweater. The directions for the heart shaped pockets are as follows:

Note: Work increases within each 3-st group by adding sts in the following order as needed: sc, dc, ch-1. Always beg and end rows with a sc. (I don't understand what they mean by adding sts in the following order as needed.)

Row 1: Ch2, sc in second ch from hook

Row 2: Ch 1, 3 sc in sc turn (3 sc)

Row 3: Ch 1, 2 sc in first st, sc in next st. 2 sc in last st, turn (5 sc)

Row 4: Ch 1, (sc, ch 1, dc) in first sc, sk next sc, (sc, ch1, dc) in next sc, sk next sc, sc in last sc, turn (7 sts).

Here's where I get lost

Rows 5-7: Work in pattern across, increase 1 st at beg and end of each row, turn (12 sts at end of Row 7)

Row 8: Work even in pattern, turn.

My questions: What is the pattern and how do I increase the stitch at beg and end.

Thanks so much for your help!