Because the whole quilt was pulling inwards in the center there was a lot of stretching to do.
I continued around each edge, constantly checking the measurements and using the square and straight edge.
When it was all square and secured I sprayed it with starch VERY WELL and left it for a full day.
I checked on it this morning and it looks great. I unpinned and it kept it's shape so now I can sew on my black border and do the machine applique on the flowers.