My sister and I both own 3.5 arecs of land that I was buying and is paid off My Mom and Step dad put both of our names on My sister was 17 at the time they did this and she is now 23 and I am now 44 she is now wanting me to either sell out or buy her out .I live on this land and can not get a loan . I told her I would buy her out . I was woundering how my Mom and dad got a way with putiing her name on the land when she was only 17? At the time? I am willing to buy her out for a far amount but was this done on the up and up?

It could have been a family partnership until she was 18.
You will have to ask your parents if you can. And state law might have changed in 6 years, as more states are cracking down on hiding assets in minors' names.
As for recourse if she wasn't supposed to be on the deed, I think you might have a tough battle, and if you did pay a lawyer to fight it the land might revert to your parents, or they would be ordered to pay overdue taxes or something.
What I don't understand is how you 'paid it off' yet she is half owner? Did she pay for her half? I know you live there and I assume she doesn't, so what exactly were you paying off all this time?

What is the exact wording on the deed? I'm not sure what problem you see in her name being on the deed. Who did you buy the property from under what terms? Have you talked to your parents?

I had a bought the land from my mom and dad and no My sister did pay any thing on the land.

So why did they put your sister's name on the title? What about the answers to my other questions?

You don't seem interested in answering questions, so.. it doesn't matter how much of the land you paid your parents for and how much she didn't pay for, your sister is half owner and can force the sale and can take half the income. So start the payment plan to buy her out.