The scene where Gretel wakes up in bed and finds Hansel passed out on the floor is especially sweet because of how natural it is; she pokes him awake to talk, and he hugs her arm and after groaning at her to go back to sleep, he weirdly rolls over under the bed . She just looks vaguely exasperated, like he likes it under there and it's normal for them. It's a perfect sibling moment.
Not to mention, he lets her have the bed and takes the floor, which, sweet.
And then, of course, their entire reunion in their childhood home. And the fact that while Gretel can't quite figure out how to tell her brother that her mother was a witch, which means she's a witch, she's not afraid to tell him. It clearly doesn't cross her mind that he would ever abandon her over it, which he doesn't — hell, it doesn't even faze him. When he finds out about Mina, completely different story, but Gretel? No second guessing, no questions of trust. Sister's a witch, okay, whatever, don't care, I am going to kill every fucking other witch out there to save her.
In the Extended Cut, there's a brief scene during the final where they kill Muriel where Hansel and Gretel pause, hold hands and just indulge in standard sibling interactions. It's adorable.