Julie Cobb has a lot of managing skills; however, she cannot take business decisions apparently. She needs to improve her skills in order to be capable to encourage and stimulate her team to work by themselves, individually but with an only propose. By the way, leadership is a science and leaders are not born. She can get these characteristics working on it.
Regarding that leader can be developed; I could promote someone as Julie Cobb to a leadership position. However, as her leader, I should give her directions to be stronger and develop her abilities for the propose of being a leader-manager. Actually, she already has the skills to manage her team. She just needs to become better on her lead qualities. A good leader has the power of controlling people to achieve anything. Good leaders have to know how to deal with people and diverse situations. As a characteristic, good leaders have to know how to encourage people and motivate them in a personal way. Remember that each person has a different thought, beliefs and personality. Most of the times, the leader needs to encourage his/her team in a particular way to achieve a result as an overall.