Dorothy throws a HUGE tantrum over this, throwing the diaper, kicking and flailing, and whining the entire time. If she's going to act like such a little baby, maybe diapers are more than appropriate for her.
Alex has to physically lift and carry Dorothy into position and has to fight and wrestle her to get her to put her legs up, but when she does, it's to give her a diaper position spanking first. Only then does she tape Dorothy into her vintage DC Amore diaper.
Once she's wearing it, Dorothy still won't agree to wear one to the test, so Alex wrestles her down onto her stomach there and pins her in position, spanking her diapered bottom until Dorothy gives in and agrees.