If she doesn't want to supply pull ups at 3 1/2 and no accidents for a year then I can see her perspective although her attitude stinks. But as a provider I know that something has to be in place for accidents that are likely due to the change. Ask her instead, to supply you with waterproof sheets which can be picked up for as little as $10. That way it is protecting your sleeping surface without the worry of regression. Two sheets give you a spare so you can send soiled sheets home to be washed for the next day. A lot cheaper in the long run than pull ups too. Honestly cutting the pleasantries, if she doesn't go for that, don't prolong the inevitable and tell her not to let the door hit her on the way out.