By saying you and your sister bought a home "14 y ago", do you mean "14 years ago"? The time frame probably doesn't change the nature of your problem but it does have a bearing on how much equity has been built up in the home.
When you and your sister bought the home, the two of you became the owners. If you alone have paid the mortgage payments, then you have simply created an asset that the two of you own in equal shares. There is no way you will be permitted to refinance the loan without her signature. You should see a good real estate lawyer right away to explore a means to remove your sister's name. If she will not voluntarily release her interest to you, the law of your state will hopefully permit a suit based on equitable principles to require a transfer of her interest to you. If that is not possible, perhaps a court ordered "sale for division" will get the job done. In such a suit, you could probably purchase her interest for a modest price. The longer you permit this situation to exist, the more complex and expensive it will become. You should see a good real estate lawyer soon.
Answered on Oct 31st, 2011 at 9:50 AM