purrpurr:So it would appear that Rachel wanted these mandrakes to: practice magic with, to get high or to bring their magical powers into the home to help her get pregnant?
Not neccessarily. Mandrake has been used medicinally for centuries for far more than the purposes that you have mentioned.
https://www.botanical.com/botanical/mgmh/m/mandra10.html
Medicinal Action and Uses---The leaves are quite harmless and cooling, and have been used for ointments and other external application. Boiled in milk and used as a poultice, they were employed by Boerhaave as an application to indolent ulcers.
The fresh root operates very powerfully as an emetic and purgative. The dried bark of the root was used also as a rough emetic.
Mandrake was much used by the Ancients, who considered it an anodyne and soporific. In large doses it is said to excite delirium and madness. They used it for procuring rest and sleep in continued pain, also in melancholy, convulsions, rheumatic pains and scrofulous tumours. They mostly employed the bark of the root, either expressing the juice or infusing it in wine or water. The root finely scraped into a pulp and mixed with brandy was said to be efficacious in chronic rheumatism.
Mandrake was used in Pliny's days as an anaesthetic for operations, a piece of the root being given to the patient to chew before undergoing the operation. In small doses it was employed by the Ancients in maniacal cases.