Claymore is a possibility, though the heroine doesn't laugh that often. Some of the antagonists, Riful in particular, are pretty droll though. On
Funimation.
The girls in Mahou Shoujotai Arusu (aka "Tweeny Witches") have strong personalities and some powers, but they're all between 10 and 14 if that matters. There are some solid adult characters in supporting roles.
Finally I'll suggest Kemono no Sou-ja Erin which follows a young girl from about eight to eighteen. She wants to follow in her mother's footsteps and become a veterinarian to magical beasts. Eventually she becomes the target of competing factions in a civil war. On
Crunchyroll.