the only way to give someone a car, pay for it, and have them on the title is like this. you would pay the balance on the car. if it has an existing lien you can't do anything but give them the car with the title in your name. however, if it is truly their car, they are not supposed to be driving under your insurance, which it sounds like you know is fraud. so, this is the only way. pay off the loan. bring your sibling to the bank with you. have them apply for the loan of what you just paid off. if they have credit, just let them be the sole name in the car. you can still make the monthly payments if you want. the bank doesn't give a shit where the money comes from as long as it is paid. that will also strengthen your sibling's credit, because even if you pay, they get credit for it.
if your sibling has issues with credit or you don't like the 1st option, both of you go and let the sibling's credit be run. if they refuse it and say a strong co-signer would get it approved, then you co-sign and request all financial things be sent to you. then, it is still not your loan, but you can pay it and put their name on the title so the car is in their name.
those are the only 2 ways for you to pay and have them on the title. they must be a part of the loan to be solely on the title when you are paying for it.