Thanks fibernut and Dot - I think I got my answer. I was hoping that I could "encourage" the sleeves to be longer, but it sounds like I'll need to either 1) reknit them or 2) ask the mom to give them a tug before drying.
Come to think of it, that's what I do with a few of my store-bought cotton items - not sure why I thought/hoped this would be different!
Thanks for the help. Jean