What do you think about me telling my relatives to stop calling and bothering my mother while we are away?
What good would it to do you if your relatives stop calling and bothering you?
They annoy her.
It is understandable to be annoyed at family. Just make sure you don't be too mean to them when you voice your displeasure to them.
So, she should stop being annoyed with them calling?
You should find out what your relatives are calling about, simply telling them to stop calling is rude. It would be better to explain to them that your mother is needing time to relax and that she will get back to them when she feels better.