I made two pairs of these, both in size 98cm. They literally fell off my dd when I put them on her. She is *tiny*, but normally a 3T will set on her hips even though it doesn't "fit" her. I would definitely double check your child's measurements versus the pattern pieces and size up or down accordingly. I didn't do the strip down the side seam instead I just topstitched the SA. I did reverse coverstitching on the pocket and a contrasting pocket lining. These went together quickly and I like the pattern a lot!