Do you have NICU experience other than the time you have worked in this unit? If not, I would strongly advise you against taking this position at this time.
RNs practicing in specialties like NICU need a good 1-2 years of full-time practice to develop the knowledge base, skills, and expertise needed to serve in a leadership position. Gaining this experience is absolutely necessary to prepare one to lead a unit where so much is unique, and so few people within the institution are capable of assisting you.
Having worked as a staff nurse, charge nurse, assistant head nurse, and nurse manager, I can tell you that the higher up the ladder you go, the lonelier it gets. By the time I was managing a NICU, I had no one within the institution who could advise me on nursing issues, because I was the only one with any significant amount of NICU experience. By that time, I had 6 years of progressive experience to draw upon, and even then, it was tough.
You sound like an excellent clinical nurse, and I believe you will make a good manager some day, but don't rush into it without proper preparation. Start out shadowing a charge nurse. When you have a year of experience, ask to be given occasional charge duties when a more senior nurse is on duty to assist you. Request conference time to attend sessions on assuming the charge nurse role.
It is also typical of hospitals to promote nurses into management without offering proper formal education on matters such as Human Resources issues, budgeting, scheduling, etc. Prepare yourself for those aspects of management, and you will do well!