Yes. Hodgkin's disease is a form of cancer of the lymph nodes, albeit a treatable cancer. Please seek care for her asap to avoid spread of the disease.
Yes. I appreciate your asking. If the other physicians who have answered have not been frank enough, please let me be clear. Assuming the diagnosis is correct (and you want two pathologists to concur), your daughter will die of her disease if she is not treated successfully.
Yes. With hodgkin's she has a good chance of curing the disease (though nothing is 100 percent) even with advanced stages. The therapy however will have its effects and risks, she should be able to live a long happy life. Her health can be effected from the acute side affects of her chemotherapy and radiation as well as possible late effects and watching for late secondary cancers.
Yes. There are several types of lymphoma, of which hodgkin lymphoma is one type. However, it is divided into several types, with nodular sclerosis type the most common. There are many ways in which your health is affected, including, weight loss, fever, chills, night sweating, malaise, fatigue, among others. Treatments are based on stage (extent of tumor) but are quite toxic.