What is expected of someone that isn’t Jewish at shiva?

Dear Rabbi
I have a very close friend whose grandmother is on the verge of death. She asked me to attend shiva with her one night once the inevitable occurs. As an Irish (non-practicing) Catholic, traditions I am used to are very different when someone dies (think Guinness and Whiskey). I know that more than anything she simply wants me to be there for her, but I would like to make an effort to, at minimum, show as much respect for her and her familys faith as possible. What is expected of someone that isnt Jewish? Should I bring a gift (or some food)?
Dear Paul,
The shiva is a seven day mourning period which should be treated precisely as such. Unfortunately even in Jewish circles it has lost some of its semblance. Several do a post funeral shindig – more in keeping with a wake but which has no basis in Jewish law. And then there is all the laughter and frivolity that typically goes on many nights of the shiva. It’s all wrong and missing the point of the paramount respect that should be shown to the deceased. What you need to do is simply be there for her, as you suggest, bring in some kosher food if so required, and that’s pretty much it.