Yes, I have advice. You can continue to focus on finding her g-spot and you can continue to be frustrated. Many women have amazing orgasms by g-spot stimulation. Others have plenty of hearty orgasms and live sexually satisfied lives without ever locating the elusive spot.
The one way to ruin a good sex life is to focus too much on a sexual goal. Multiple orgasms. Ejaculation. The goal of sex should be to connect with your partner, to enjoy yourselves and to make each other feel good. Sure, orgasms feel good, but there is much more to sex than orgasm. And there are many ways to have orgasm without ever touching her g-spot.
Having said that, there are ways to locate your partner’s g-spot. Has she located it herself? Have you located yours? That is the place to start. Find your own g-spot, here's how.