Bipolar mom ran away

So my moms been having an episode i would say at least from February. And now she ran away from home and idk when she’ll come back. My sisters are planning on bringing a psychiatrist home to inject her. Im not sure which injection, but they say it could be the only thing that works bcs she has done ECT couple of times before and doesnt take pills. She refuses it and her whole illness although she has been diagnosed. She is 50 years old and her first episode has started as early as maybe 13 years old or 14. Her sisters (4 of them) take psychiatry medications since they were young but my mom doesnt take it because she hasn’t been taught.

Now my question is will those injectables actually work? Because im having such a hard time and have exams at the same time as her manic episodes and idk what to do. How long will the injectables take to work? How do we convince her to take it after it wears off