Shirayukihime no Musume to Shitsuren Ouji: Onee Joou to Shirayukihime Gaiden

Emilia, the daughter of Queen Snow White, falls in love with Luka, a prince from a neighboring country who was in love with Snow White!
The black-hearted prince, who had given up on on love after being rejected by Snow White, is now being aggressively courted by the innocent girl!
The child of the pure-hearted king and the innocent Snow White turns out to be quite the little princess!
It's the beginning of a new pure-love story with an age difference!

(Source: Pixiv, translated)