Also, because she submitted the application after her visa expired, she became an overstayer in the UK on March 8th and is NOT covered under 3C leave.
This means that she is not legally allowed to work anymore, so if she is currently working, she must stop immediately. If she continues to work, and her employer is found to be employing an illegal immigrant, they can be fined £10,000 and face 2 years in prison. She is also not entitled to use the NHS for 'free' anymore.