Now start sewing. Sew the t-shirts into rows (I have 4) and then sew the rows together. When you are finished, cut the rectangle of t-shirts so that all of the edges are even if needed. Now cut out a piece of batting and a piece of cute cotton material the same size as your t-shirt piece and layer the material right sides together and then the batting on top of that. Pin together and sew around all the edges leaving an opening for turning. Trim the corners and turn right side out. At this point you could hand-sew the opening closed or machine sew around the entire blanket to close the turning hole.
Finally, finish off with some yarn or embroidery floss ties. I did mine about every 3 inches which I marked with a pen first to easily know where to place each tie. Also I had a hard time pulling the yarn through my blanket until I started using a much bigger needle. Then it was easily done.
I think she is going to love this blanket. It is so cozy and beautiful.