There is a possibility of compression of one of the nerves which is supplying hands.. most common being median nerve, a condition called as Carpal Tunnel Syndrome..
Does the pain/numbness increase when she bends her hand at wrist level..
Next Steps
She needs to get some investigations done to find out the exact cause.. A test called Nerve Conduction study.
Health Tips
Avoid lifting heavy weight or doing any work which is causing discomfort