In my story's world, witchcraft is a respected institution, with the most powerful practitioners being at the top echelons of society. Due to this, society traces its lineage through matrilineal lines. There are five types of magic that spells revolve around:
Enchantment Spells – These are spells designed to capture cosmic power within a crafted item, so that its power can be called upon in times of need.
Scrying Spells – These are spells designed to allow a user to perceive in ways that go beyond his fve senses.
Protection Spells – These are spells designed to ward a user, object, or location against a variety of possible harms
Transmogrifcation Spells – These are spells designed to fundamentally alter or control another being
Transmutation Spells - Changing the makeup of different materials or combining them with others to make new forms of matter.
A witch has the power to summon a familiar by using her body as a conduit between the mortal and ethereal plane. These powerful spirits are forever linked with their master, and used in a number of ways, such as magical batteries and amplifiers, repositories, or for battle. They also give one a depper and more intuitive sense of magic, allowing them to understand and perform spells that were difficult or impossible for them before.
Familiars are created through an advanced, complex spell that requires various actions and takes the form of a year long ritual. It begins with a spell that infuses the witch with ethereal energies which gestates into a spirit. Over the year, the witch performs multiple steps to mold and shape the familiar into the form she wishes it to be. The ritual culminates with a ceremony in which the daemon is birthed into the world. Familiars are prized in society, and are a symbol of status and power in the world. They represent the expertise and devotion of the witch to her craft. However, they are very rare among witches.
The stipulations for this spell:
The witch in question must be of childbearing age and must have never given birth before.
The witch must have accumulated enough mana over the years to perform the spell. Mana is accumulated in life through age, as well as training in the use of magic.
Based on these parameters, why would witches choose not to create Familiars? What would be the cost for this type of magic?