Wanab, she's not too young! Teach her the running stitch etc. I am teaching stitches to my 6 year old and her 5 year old friend. They both do fine. The 5 year old pays attention and does really well with it. They are learning to use machines too. My daughter has started her first quilt, a 9 patch. Getting a correct 1/4" seam is a challenge for her, but then she just learns to use the seam ripper. It's all good. She asked for sewing stuff for Christmas. Your granddaughter will treasure the skills she learns from you just as I treasure the skills I learned from my grandmothers. I say go for it!