Deloris and the Reverend Mother at the end of the first film. Yeah. That scene.
Don't forget the scene where she defends Deloris as a true nun and "a model of generosity, virtue, and love".
"Out of bed, you Daisy head." That whole scene with Mary Robert, actually.
The scene after the first choir practice, when Deloris is lying in bed listening to all the nuns practicing their chords, and it ends with Mary Robert hitting a perfect, beautiful note. The smile on Deloris's face really sells it.
The look of pure joy on Mary Robert's face after her first solo during "Hail Holy Queen".
Which leads to another heartwarming moment when you can tell she has immense confidence in her voice during her other solos. (And then immediately afterward she's blushing and trying to cover her face, like 'What did I just do?')
Well, heck, every scene with Mary Robert is Heartwarming.
In universe, how the nuns feel after going out into the community after being cloistered for so long. They long to do good works and now they finally get the chance to revitalize their run-down neighborhood.
After the kidnapping scene happens, the convent is wondering why anybody would kidnap a nun. Reverend Mother decides to come clean and reveals that Mary Clarence is actually a lounge signer named Deloris who has been placed in Witness Protection after witnessing a murder. While the nuns are stunned and a bit upset about being lied to, Mary Roberts declares that she doesnt care who Deloris really is, she helped save the church and the choir. Mary Patrick and Mary Lazarus then states they won't leave saving her up to the feds if they can help it. All the other nuns, including Reverend Mother, agree and immediately set out to Reno.