It be sweet if Jane react to Rainbow’s accidents with a smirk before helping her.
And it be nice if she gave Twylight and co a firm yet fair scolding for hurting her including the Marer Do Well and Walking Dead hoaxes, Rarity’s rash wing stunt, Twylight’s puppetry of the swamp and cheerleader affairs, Applejack laughing her in the Apple-Bucking episode, Pinkie’s pie torture, Rarity forcing dresses and corsets including the one with Zephyr, and more. Zero thrashing or threats. She gives them a firm yet fair one; similar to Mufasa with Simba, especially with the part how the most severe part be how they endanger many with their wrong choices. She also calls Rainbow their sister, showing she sees family in spirit more than blood. And zero punishment, because their punishment was being force to see many suffer. And instead of telling them to stop being crybabies, she hugs ’em.
It be ncie fi she react this way to Rainbow singing a rallying song; reacting as with motherly pride. And also joins in the song.

It be sweet if Jane was an aunt figure to Rainbow, teaching her many things.
it be sweet if she was reacting to memories of her and smirking.