CLL runs a very variable course. It is still generally thought that CLL cannot be cured but even so many people with the condition live for 10 or even 20 years. As a high proportion of people who are found to have CLL are elderly it is quite common for them to die from other illnesses, as time goes by, without having had any real problems from their leukaemia. It is often the case that CLL remains inactive, or smouldering, for years with the only abnormality being and altered blood count, with no other symptoms or problems. For this reason it is common practice to delay any treatment until either blood tests show the CLL is becoming more active or symptoms, such as fatigue, weight loss or infection, develop.
Treatment relies on chemotherapy.
This has few side effects and is given as a tablet. More recently a newer drug called fludarabine has given very good results in controlling CLL and is being increasingly used. Combinations of fludarabine and other chemotherapy drugs are also being tried. A number of clinical trials are going on to test these compounds to see if they improve survival. So the advice from your mother's doctors, that she doesn't need treatment at the moment, suggests that her CLL is inactive at the moment.