If you back them with fleece (in different colors) you can add borders till the width is about 55 inches, whatever length and then sandwich with fleece. No inner lining is needed, fleece quilts beautifully, washable, comfortable, warm, etc. Binding would be whatever you have left from the borders, OR, piece the border fabrics and make the binding out of all of the fabrics.
They are adorable and will be well loved,