If you miss her so much just go visit her at Juvie, as a visitor not as an inmate.
The problem with Kant is obviously tied to his religious background, something that separates him from Hume, since Kant believed in free will he was able to go with the categorical imperative, however free will is an illusion, we are bound to follow the rules and experiences that have been given to us, social and physical determinism get in the way of the idea that someone can just will their own behavior.
The second problem with Kant is that his imperative was unrealistic and impossible to maintain, at one point you will break it, it is great when it comes to trying to solve some moral dilemmas, but horrible at other times, if Nazi's are looking for Jewish family that you are hiding at your house? what should you do? lie to the officers to save the Jewish family? or tell them the truth despite knowing that they would be killed? well lying is a depravity of the soul...