Thanks everyone for the help. I'm still looking though.....
The Missouri Star version isn't quite as large as my friend wants to do, and it is more scrappy which also affects calculations.... I guess I'll get the pencil and graph paper out (again).
I already did a calculation but I was hoping for some confirmation that my math was correct. My friend is on a limited budget, wants a bit extra "in case" but I don't want her to have too much left over, or even worse - end up short!
Maybe I can find someone with EQ to help out....
But I really appreciate all the help....