What do I say?!

Ugh. So as most of you know my parents do not live nearby. That means someone is always traveling to see the other person. This year it has been me and my little one. Three times since Christmas. So Chris and I thought it might be nice to invite Grandma to come visit and we would fly her out.
I guessed incorrectly, I think.
I was discussing this topic with my Mom and she asked me how much vacation time I get and if I had any left. I answered her and she asked why didn't I just come see her. To which I said I am teaching a Spanish class until the fall and no one else can teach it, also I have my Preschool classes. She said and I may be misquoting a little because I am ornery about it "I don't know what the big deal is, you are just a glorified babysitter..."
I know that is the perception many people have in regards to my job and I have learned to shrug it off. Usually. But my own Mom?!
Now I am at a loss, do I say anything? Do I ignore it? Do I eat a pint of ice cream?
These are all things I need to remember so when Gabby is older- I think about what I say and how I say it, so as not to hurt her feelings.
We'll see how that goes too.... :)