Angry mama

Caldera has despised ponies ever since she first met them. When Smolder started attending friendship school in Equestria, she was incredibly dismayed. If it weren't for her daughter's fondness of the place, she wouldn't have tolerated it. But one day Caldera received upsetting news: Smolder wasn't coming home to celebrate the Feast of Fire with her family. This wasn't like Smolder at all!
Caldera's fears were confirmed by a letter she received from her daughter.

Those filthy ponies were holding her captive! It was at this moment Caldera realized she had been too permissive. It was time for her to pay this Headmare Twilight a little visit...

Meanwhile Smolder was celebrating her first Hearth's Warming Eve with her friends at school. She had given an accurate account of the Hearth's Warming Club events in her letter, including the collective punishment. She also confided in the letter that she missed her family and that, despite being happy to be with her friends, she had felt some peer pressure to stay at school, even after the punishment had been lifted.
As it turned out, Smolder wasn't the only student who wrote home about their mixed feelings. Irate guardians had been giving Twilight a piece of their mind all week. Yona's parents were particularly difficult to manage.

Just as Twilight had finally finished placating them, Pinkie Pie wondered out loud, "why do I hear boss music?"

Moments later Caldera arrived, towering over the other creatures present. She let out a mighty roar and commanded Twilight to show herself. Of course, the princess of friendship obliged. Caldera demanded an explanation and was less than satisfied with Twilight's response. Having heard enough, she decided she was done with this school nonsense and gave Twilight exactly thirty minutes to evacuate the building before it was reduced to ash.
Students and faculty hastily made their way to safety, as Smolder spent the next half hour pleading with her mother to change her mind. Caldera relented right before time was up, but she warned Twilight that if she made another mistake like that, Smolder wouldn't be able to save her precious school. With that, she left.

As time went by and Smolder appeared happy at school, Caldera grew less worried about her daughter. But Twilight never worried less about Caldera.