New Knitter with Baby Poncho Question

Hi. I’m a new knitter and I’m attempting the baby poncho from SskeinS Knitting Pages (, adorable pattern!!!). I let my friend choose the yarn for her daughter who is 10 months old. It’s chenille, so it’s a bit thicker. I thought I would compensate by using an 8 needle (I think I got that backwards). So what width and length would you recommend the rectangles? I have so far cast on 24 and have stockinette stitched 58 rows. The width of the rectangle is 11. It seems like she’ll be 4 before she can wear it. Any Recommendation Are Greatly Appreciated THANKS!

Since you have a lot done, use it to determine how many stitches per inch you’re getting with the yarn and needles you’re using. Then multiply that number (stitches per inch) by how wide you want the rectangle to be–cast on that many stitches and you’re good to go.

Thanks I appreciate the help!!!