Ok If she discovered it by finding the warts then most possibly it is one of the thousands of types of HPV (including the warts that you get on your hands) that DON'T cause cervical cancer. There are only 6 types if I remember right that have been known to cause cervical cancer. Also if she goes for bi-yearly exams and gets them all removed as they develop then her risk of them developing further into cervical cancer is very low. HVP is the same virus that causes warts on your hands. It's a bit more tenatious when it takes hold in the genitals. It can last from 6mo's to about 3-4 years. The only treatment available is removing the warts. This can be quite effective because the visible warts are pockets of the virus and highly communicable. The only way to infect other's with this particular strain of the virus is by physical contact - ie. sex. Your sister really should respect others and avoid sex with them until she is positive, by word of her Dr, that she is clear of the virus. One good thing about this virus is that once you get rid of it you are immune to that particular strain in the future.
Don't panic - if she is faithful to go to her Dr and get checkups and doesn't have sex and spread this then most likely all will be fine. It does take time to develop cervical cancer from HPV. IF she goes bi-yearly they should be able to prevent it. It sounds to me like this particular strain isn't the type to put her at high risk.
CDC
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