Upgrade or change to prime lens?

I have a Nikon D3100 and believe that I should upgrade my camera to get better pictures. My partner tells me that I should use her prime lenses to get better images rather than just using the lens that came with the camera.

If you want to keep your partner happy - do as you're told, lol!

Seriously - lens quality is more important than the camera body in producing good images (assuming in both cases the photographer knows what they are doing).

Your partner is right - you are better off borrowing lenses & seeing what you can do with a prime rather than considering an upgrade at the moment.

Repeat this 100 times: "It isn't the camera its the photographer."

Your partner is pointing you in the right direction by offering use of her prime lenses. Even the low-cost Nikon AF-S 50mm f1.8 prime will give you better results than the usual 18-55mm f3.5-5.6 zoom lens that came with your camera. That isn't to say you can't make good pictures with it its just that a prime lens will always give better image quality.

In my opinion the best upgrade you could make at this time (other than buying prime lenses) would be to replace your 18-55mm f3.5-5.6 zoom with the Nikon AF-S DX Zoom-Nikkor 17-55mm f2.8 lens.