How often should you visit your grandma if she lives 400 miles away and she's 79

Question

i say twice a year at most. my girlfriend says more than that.

Answer 1

Whenever you wish.  If you feel like it's a waste of time visiting your own grandmother, then shame on you.  

Answer 2

shouldn't you visit only when you want to? she lives 400 miles away, so it isn't like it's cheap to go see her, but you should see her when you get the opportunity.  no one lives forever...