What is the ruling on a woman growing her nails long?

Trimming the nails is part of the fitra (innate disposition/natural inclination) that Islamic law encourages, based on the Prophet's (peace be upon him) saying: "Five are from the fitra: shaving the pubic hair, circumcision, trimming the mustache, plucking the armpit hair, and trimming the nails." Lengthening them is contrary to the Sunnah (definition) and is a cause for dirt to accumulate underneath them. Furthermore, the main reason for keeping them long is often imitation of disbelieving women. The Prophet (peace be upon him) set a time limit for trimming the mustache, trimming the nails, plucking the armpit hair, and shaving the pubic hair, stating that they should not be left for more than forty nights.