Don't we all just want a quick sewing project every now and then? The Victoria can be sewn without the buttons in the back bodice. The jumpsuit and dress are easy to put on the child even without the buttons.
In the back bodice's pattern piece there is a black dotted marking with the text "on the fold here for whole back bodice". When you trace the size onto tracing paper, do mark this line as well. And then when you're cutting the fabric, place the pattern piece on folded fabric, with the dotted line towards the fold, so that the pattern piece will look like the red line below. We have then removed 1 cm (3/8") seam allowance from the center back.
So you would then instead cut 2 back bodices on the fold (one in outer fabric and one in lining). And when you sew them, you sew just like you do with the front bodice, in step 4.