“My sister and I co-own a home. She wants to take out $25,000 in home equity for personal use because she is unemployed. She told me if I won’t sign she will get a lawyer and force me to buy her out which I cannot afford to do or I would. Can she force me to buy her out ?”
She can’t force you to buy her out, but she can force you to sell the property to a third party if you won’t. That’s called a partition action, and it’s the right of co-owners generally.
I would suggest talking to a good mortgage broker. There are some lenders now that will lend to a single TIC (tenant in common) without both parties being liable on the debt. Maybe your sister can qualify for one of those, and the loan would then be her problem alone, secured only by her interest in the property. Of course, given that she’s unemployed, it may be difficult for her to qualify, but it doesn’t hurt to ask.