The yarn is Artyarns Cottonspring, which is a nice blend of 80% cotton and 20% wool. My preference is always for wool, but I have a feeling this mother may not appreciate wool.
I actually swatched for this to test machine wash and dryability.
There was some shrinking (I was tempted to just say shrinkage...but...), mostly lengthwise,
so I compensated with some extra length. Took a long bus trip and managed to finish the body.