Sonata Dusk, once lost and unsure, is living proof that people can change. When she realizes how hard it is to make amends and regain the respect of her peers, she will make an attempt to do some good, so the students of Canterlot High could see who she really is.
Setting up a café sounds like a great start.
Sunset Shimmer is living proof that people can change. When she finds out that the Dazzlings are being expelled for their crimes, she will make an attempt to understand their past and salvage their future.
Sonata has a plan to regain the respect of her peers. It involves Sunset Shimmer, tea, and a promise of small eatables.