As someone once said, "Tough friends last longer."
Again, good on Betty for forcing the two miscreants to face up to what they did. She did have to hurt Victor's and Milagros' feelings like that to make them realize how wrong they were for sneaking into Wilfreda's. Now they have to dread the little witch herself adding to their shame, but what may be most uncomfortable is if Wilfreda doesn't huff and puff at them for it. Then these two will realize that they hurt someone who's also a very good person, and that sting will teach them more than anything. (That, or being turned into animals. If Wilfreda is checking the book to make sure it's okay and happens to be on the Polymorph Spells page… )
Beware the quiet ones, as they say.