SKIP the gussets according to the pattern. After the ribbing, knit four rounds.
Rnd 5: knit 3, pm, m1, k2, m1, pm, finish the rnd.
rnd 6 and all even rnds, knit.
rnd 7: k3, sl marker, m1, k4, m1, sl marker, finish rnd
rnd 9: k3, slm, m1, k6, m1, slm, finish rnd.
Continue until you have 10 stitches (for child's mitten) between markers. Knit one rnd.
Next rnd: knit 3, slip next 10 onto a stitch holder, increase with backwards loop for 2 stitches, continue.
When the mitten is done, put the 10 thumb stitches on needles, pick up 12 more. Continue in pattern as best as possible.