User blog comment:NotNone/What is saving too much mana in lane/@comment-3476718-20130510130657

Zyra is a pusher by nature. Players aresn't.

If she's "saving mana", it's either because she's waiting for the right time to lay down her full combo, or otherwise saving it to help you (though pushing would be a way better idea).

Besides, pushng would put you in danger of being ganked (which pusher supports usually are).

Or she may just be a terrible player. Does she buy wards?