Getting to manage models?

until now i used to be just a photographer then i began working with this girl that is utterly amazing, we have managed to go semi pro. im very confident she can become the new face of modelling this decade. im thinking of getting her to go proffessional, how may i do this and still be in the picture? i want to become her manager and get to introduce her to proffessional modelling agaencies. what do agaences do? how can they help. with modelling agencies can i still be in the picture? what is the step by step approach to get her out there? thanks