Just be honest and confident with who you are and what you have. And maybe surprise her once in a while by doing something grown up or more mature, like a real nice dinner.
She can't expect you to behave like a 30 year old with a career, so don't pretend to.
Knowing your own limitations and not considering them to be limitations is part of being a man.
I've dated a few older girls, and will generally tell you they seek out a younger guy because they are baggage free and innocent.
I'd be conscious of that fact and if your relationship progresses don't let her use you or take advantage of your inexperience.
I just want to add on a more positive note that dating an older girl can be a good thing, you can learn a lot, not just sexually
Keep it all in perspective I guess. Take it slow, you've probably had fewer relationships than her and you're motives for getting into a relationship might not be the same (she might be more serious etc..)