Hello Mary, lovely to hear from you. As you can see from the comments above yours, Curlytop and others are great for advice. But I want to let you know I'm currently surfing the web for all manner of tutorials and instructions and patterns and I'll post the links in an Article On Making Quilts from T. Shirts, next Sunday 7th April. So keep an eye out for that article, I'm sure it together with all the helpful advice you get on this forum, you'll be able to make a lovely quilt for your granddaughter.
Cheerio for now