Here is the favourite joke of a girl I used to know:
A woman in liquor production
Owns a still of exquisite construction.
The alcohol boils
Through magnetic coils.
She says that it's "proof by induction."
The joke worked on ME, I can tell you that, but you can see this depends on the audience right?
Just relax, treat her like any male friend. Show interest and enthusiasm towards her and be interested in what she has to say (If this is hard to muster, you're probably not interested in her!), ask questions that follow on from the current topic rather than having prepared material. If she is quiet and won't talk, take something she said earlier and talk about it, IE 'What you said earlier about x, that is really interesting because I was thinking about Y, blah blah blah, what do you think about Y?' and you wont run out of things to say. Laugh and enjoy yourself and she will think you are funny (If she likes you).
If you suck at the art of conversation, actually practice with friends and family in a 1-1 setting. The skill is really no different.
So what went wrong Ivory? Dish.