I made a Princess Cadence-Shining Armor baby

Her name is Crystal Spear, two parts, one for each parent and something that represents them.

When she was younger, she was a bit of a spoiled brat, and loved the idea that she was a princess, but she came to hate how everyone wanted to do everything for her, because she was meant to be a leader, which meant she could do whatever she wanted. Not everyone do it for her.

Eventually she realized this was tied to her princess title and began to resent it. Instead of continuing in her mothers footsteps, she followed closer to her fathers and became a Crystal Guard, eventually becoming a Captain.