You can make a booking for friends or family from your Careem account on the Careem website.
Simply sign in at www.careem.com, and select "guest" as the passenger. Fill in their details and complete the rest of the steps just like a regular booking.
The booking will be made under your account and charged to your payment method selected, but the Captain will receive your guest's details instead of yours. Select "Cash" as the payment method if you want your guest to pay for the ride in cash.