Was Eve actually created from Adam’s rib? What is the meaning of the following hadīth?

Allah 's Apostle said: Treat women nicely, for a women is created from a rib, and the most curved portion of the rib is its upper portion; so, if you should try to straighten it, it will break, but if you leave it as it is, it will remain crooked. So treat women nicely. (Bukhārī, Kitāb Ahādīth al-ambiyā)

This is not true. The first verse of Sūrah Nisā explicitly states that the first man and woman (Adam and Eve) were created directly by the Almighty:

O mankind! Fear your Lord who created you from a single soul and of like nature his mate and from the two scattered [like seeds] countless men and women. (4:1)

Secondly, in Arabic the words "created from" do not necessarily refer to the substance of creation; they can also refer to the nature of something. For example the Qur’ān says that man has been created from hastiness. This does not of course mean that man's substance is hastiness; it only refers to his nature.

Thirdly, if all the texts of the Hadīth you have referred to are collected and analyzed, it becomes evident that the Prophet (sws) has compared the nature of a woman with a rib. The comparison subtly alludes to the fact that a woman's nature is very delicate and tender as well as a bit stubborn. The Prophet (sws) has advised men to treat them tactfully keeping in view this nature. Instead of forcing them to accept a particular point of view which will only bring out their obduracy, men should try to convince and persuade them.