Absolutely! Any additional experience you can obtain is positively recommended. It will provide a great opportunity to put into practice what you have studied during lessons.
The family member supervising you must be over 21, be qualified to drive the type of vehicle you want to learn in (for example they must have a manual car licence if they’re supervising you in a manual car), and they must have held their full driving licence for 3 years (from the UK, the EU, Switzerland, Norway, Iceland or Liechtenstein).