Medications can always be upped and changed and it's rare anyone can stay on the same medications for years. Some people can manage without medications. Anything is possible.

There are things she can do to help her stability... Learn "triggers" , Coping skills , Meditation, Mindfulness, Self grounding, exercise , diet.

Bipolar comes and goes in cycles but the above things can be used daily that may help her severity come down and even out some.

Does she see a Therapist on a regular basis?