Dear Tara, 

I will try to answer your three questions 

One: consecrated singles may consecrate themselves through vows or through promises. It depends on the particular group or the individual case. You should simply ask the Catholic Core which they take, promises or vows. 

Two: as regards your mother, you might ask her the reasons for her reservations. She may not be against the idea of you giving your life to God, but just the particular form in which you want to do so. It is easy to think that lay consecration is inferior to sisterhood, for example, and something as simple as that might be making her less enthusiastic about your choice. Or she may be concerned about something else - perhaps she thinks your decision is all emotion, or ill-timed, for example. If you ask her why in all probability she will have something useful to say to you. Never underestimate a mother's intuition. 

Three: the big one: when? It's good that you have a spiritual director, and I presume he knows or can find out more details on the Catholic Core. He is better placed than me, knowing you and knowing them, to give you a concrete answer. Let me just encourage you to do one thing: you are getting a fairly strong interior push towards this vocation. If your spiritual director has no strong doubts about your possible vocation I would encourage you to presume you have one, and take the next steps on that premise. There is a temptation to discern endlessly (and needlessly). It is so comfortable: we feel good because we say we haven't closed the door to God, but at the same time we do nothing concrete, sacrifice nothing, we can waste years even, because 'we are discerning'. If the Catholic Core's formation program requires you to go to college before joining don't go to college to prolong your discernment. Go because that is the next step in the vocation that you are answering, and I am sure you will find Steubenville most helpful. 

God bless.