About 5 months ago I got a new car, my mom cosigned for it but I make the payments and its insured in my name.

It was bought in New Hampshire but we live in Vermont. It has both of our names on the registration and the title.

Can she legally take the car from me?

The car is literally the only thing I have, if she takes it I won't be able to get to work, I'll lose my job, and I have no money saved up right now nor do I have enough credit to get a new car.

I don't know what to do.

Insurance means nothing... she is an equal owner in it, she cosigned and has her name on the title as well... its as much hers as yours... How old are you? That actually matters a great deal.

Insurance means nothing...she is an equal owner in it, she cosigned and has her name on the title as well....its as much hers as yours...How old are you? That actually matters a great deal.

I'm 19, but wouldn't me making the payment also mean something?

Nope... the names on the title establish ownership. A cosigner has a legal obligation to pay if you fail to... they are also considered a legal co-owner as well. only a fool cosigns and doesn't have their name on the title as well. Just like a house.. they can force a sale if they desire... unless you are able to buy them out of their half. I'm assuming that's not the case.

Is there a reason she's threatening to do this?

Neither one of you can 'take' it from the other. I have a feeling something is missing from this story.
First - do you owe her money outside of the car? Rent, food, utilities. Other?
Second - was there a down payment? Who paid that?
Third - are you fighting? Does it involve moving out?