A quick little descript of the story for this drawing:
Both of Flurry Heart's parents supported her interest of being a guard. But while Shining Armor was super happy about it and happily mentored her, Cadance had her doubts. A guards life is risky (seen it through Shining enough), not something she wanted for her daughter. However, she kept quiet, because this was something that made Flurry really happy.
When Flurry got older time to time she participated in the guard cadet's training session. And than one day there was an accident. Nothing major. Just a trip with a bit dirt and few scratches. Cadance hearing about it immediately went to the traning grounds. Flurry said that it's not a big deal and she can walk it of easily. This is when Cadance decided to be a bit more honest with her. She told Flurry how pround she is of her and her dedication, but how much she is worried about her.
Flurry promised she will be more careful, but couldn't help but feel guilty about the whole guard thing after that.