OK, let's not scare the shit out of the OP.

Yes chemo carries side effects but what happened to your grandmother is rare and there is also a very good chance without chemo she would of died much sooner.    This is why the OP's mom will probably be seeing a cancer specialist that can give her all the pros and cons and decide what the best treatment is for HER.  She may not even need chemo or maybe just a small dose.