Tensei Reijou wa Nigedashita Mori no Naka, Skill wo Kushishite Sempuku Seikatsu wo Mankitisusuru.

Lara was abused because of her sinister appearance of black hair and black eyes and her inability to use magic.
One day when she was 14 years old, she attempted suicide, which triggered her memories of a previous life, and she decided to run away from home with her 6-year-old half-brother instead. While on the run, they unexpectedly meet a powerful (and fluffy) guardian, and they begin a life of hiding in the forest. For the naive and frail siblings, life in the forest should have been quite harsh, but thanks to the "skills" they acquired, they are able to enjoy comfortable slow life.

(Source: Tugikuru, translated)