gossamer, if I may, I'd like to offer a suggestion that may be really useful to you in future shots like this...
I have a friend who owned a rather nice camera, but thought it was a lousy camera because he disliked so many of the pictures that he took with it. I looked at his images and it turns out he was usually complaining about the quality of his outdoor portraits.
We happened to be sitting out on a patio in later afternoon lighting as he was describing his problems. I asked him to hand me his camera, made a quick change to it, pointed at him, snapped his picture, and handed the camera back.
He was "wowed!" by the image he saw on the review screen. He claimed it was "the best image" he'd ever seen the camera take.
What did I do?
I turned on the flash and then dialed the flash exposure-compensation adjustment to "-1".
Why?
The difference between sunlight and shadow is extreme - a bit too extreme for the camera. If the camera has the exposure set correctly to capture your subject of interested -- which in your case happens to be in shadow, then it will over-expose the background. If the camera is exposed nicely for the background, then the subject you care about will be too dark.
When you turn on the flash, you fill in those shadows with some light. You are reducing the difference between the highlighted areas of the photo (in full sunlight) and dark areas of the photo (in shadows) so that the difference is no longer extreme. This creates a more balanced look.
The reason I also dial the "flash exposure-compensation" (aka FEC) down to "-1" (sometimes I dial it down to -2/3) is because I don't want the flash exposure to "look" like a flash exposure. I want the sun to to be the main source of lighting. It is actually possible to use camera & flash settings that can over-power the sun and make your subject look brighter than the background. If I set use a default flash exposure compensation then the flash camera will attempt to eliminate the shadows. I don't want the shadows to be completely gone -- an image with no shadows looks flat. You get the sense of dimensionality in the image due to the play of both highlights and shadows so I want the shadows... I just don't want EXTREME shadows. When you set the FEC down to "-1" it means you want to under-expose the flash by "1 stop" Each stop is either the halving or doubling of the amount of light (depending on whether you are adding or reducing). So "-1" means you want 50% of the light that the camera might normally use (and that would be an amount of light that would attempt to eliminate the shadows completely.) Since the sun is effectively at "full power" - or 100% power (once the camera is exposing for a daylight exposure) and the flash is at 50% power, it means you have a lighting ratio of about 2:1 (sun to flash) and that's not bad. Sometimes I'll just adjust it down by -2/3rds which provides more of a 60/40 split in light rather than the 66/33 split.
I'd encourage you to play with using flash outdoors and also play with learning to use the flash exposure compensation feature on your camera.
Two more things...
1) The built-in pop-up flash on any camera is not particularly powerful. It's ok as long as the subject is within perhaps around 10' from the camera (this varies depending on the ISO setting but you would not want to use a high ISO setting when shooting in full sun.) An external shoe-mounted flash is easier to work with because it can provide enough power.
2) I don't always use this technique outside... I mostly use it for shooting human subjects when they are outside either (a) in strong mid-day sun (ideally a photographer prefers to wait for a better lighting conditions, but we do what we have to do.) and also (b) in situations where the subject is in full shade (perhaps under a tree) but the background is in full sun.
Here is an example:
Though it might not look like a "flash" image; it is... this is using a flash with the FEC at -1. This was a candid shot of an actor taking a break. He's in shadow and I want to make sure it actually
looks like he is in shadow. I don't want to lose the shadow. But without the flash, that background would look horribly over-exposed (notice it doesn't look over-exposed). I've brought the difference in "light" and "shadow" much closer together so that the camera doesn't struggle with the "dynamic range" needed for the shot.
You will need to make sure you know how to force the flash to fire. I'm not a Nikon shooter so I don't know your camera. But many cameras won't let you force the flash to fire if you are in full automatic mode... but it will if you are in Program, Shutter priority, Aperture priority, or Manual modes.
Also... don't forget to change your FEC setting back to "0" when you are done or the next time you're shooting indoors and need the flash (not as "fill" but as a main source of light) you'll wonder why your images are all dark.