NJ residents under 18

So my sister lives in NJ and she's only 16. By the time she gets her EAD and SSN, she'll need to wait 6 months with her permit before getting her license. Since our parents are also undocumented, do any of you NJ residents know how she would go about driving with her permit? NJ law states that you must drive with a NJ licensed driver over 21 and you must also buy those plate stickers, letting people know you're driving with a permit. Well my parents use a pennsylvania license plate, since they are kinder to "international" drivers, so would it be smart, and legal, for my sister to use their car? Would it be smarter for her to just get her own car? And if it is, how old must she be in the state of NJ to be able to register and insure an automobile? If anyone knows, or any of you younger Dreamers are in the same boat, let me know! I live in PA, so I know far more about our DMV than New Jersey's. Thanks guys!