NOTE- The reason Burnkit is a calico is because calicos are mostly white cats, while tortoiseshell cats don't have white on them. 

Snowlion bared Thunderclan three healthy kits, A black tom (Coalkit) A white and cream she-kit (Blossomkit) and a calico she-kit (Burnkit) They shifted a lot  and it took them a while before there eyes opened. It must have been hard for Snowlion, she was a gentle queen who took time and compassion for her kits, she never had a hard time with them though.

Burnkit was the smallest of her litter. While Coalkit was the biggest. Burnkit's littermates never played with her, and treated her like she never existed. Snowlion would play with her, and sometimes the warriors would come and play. She diden't  know her father, but Crowstar would fill in for him. Blossomkit and Coalkit said the only reason he played with her was because she was small. It upset her, but she still played with him despite what they said.

It was the day before they were six moons, Blossomkit and Coalkit left to sneak off and explore, they said they diden't want to wait like small kits, and show the other clans how much better Thunderclan was. She wanted to come too, but they said she was too small. They never returned. Snowlion was washing her pelt. She looked at Burnkit "Where is Blossomkit and Coalkit?" Burnkit wanted to tell her they snuck off. But they would just tease her and call her a mouse-brained tattle-tale. "There, uh... In the elders den listening to a story!" She yelped. Snowlion diden't look impressed "Very well." She replied. Burnkit took her advantage. She snuck off almost caught by a hunting patrol, but she was going to find them and show them she was worth it!