Adenocarcenoma (esophageal cancer from reflux disease) is very slow to develop. However, given your sister's age, she has a long time to live with reflux, if in fact she has reflux disease. There is so much she can do with diet and lifestyle that will allow her to manage her disease - but at 10 she will need your support. Both of you should commit to understanding what you can do to manage the symptoms and underlying causes and get on it! Be sure you know her GERD stage - its important to know where you are before you decide where you are going. Best wishes!