What is the ruling on naming a girl "Sandy" if it carries meanings specific to Christians, or meanings such as "son of Alexander" or "sandy," and must it be changed?

It is impermissible to name children with foreign names specifically belonging to disbelievers. The prohibition is further emphasized if the name's meaning is ugly or polytheistic, such as the name "Sandy," which is said to mean "savior of humanity." Imam Ahmad disliked naming with Persian names for two reasons: First, the fear that the meaning might be prohibited. Second, the dislike of becoming accustomed to speaking other than Arabic, because the Arabic tongue is a symbol of Islam. Imitating their naming practices is a major sin, and if it stems from a belief in their superiority, it is a grave danger that shakes one's faith. Repentance from this and changing the name is obligatory.