I think overall your lighting is fine--you lucked out with decent ambient or you used open shade / placed the sun well. The light is lacking in drama a little bit, but if it was windy your off-cam stuff was probably going to hamper you more than help--presuming you're running solo.
Some critique:
1) leading lines are helpful. Note how his right arm creates a line that leads to his eye. That works. But note how her right arm creates a line that leads to his, well. There. Her hand being occluded here also seems a little odd.
2) This seems a little cool and could easily be warmed up. Even if the day was cool, why depict that in the shot ? His cupping of her arm is unnatural. His expression seems surprised--not quite ready for a photo to be taken. He needs to relax a little--something you can help by getting some convo going, making fun of him, making fun of yourself, finding something in common to talk about. Her hair should also have been swept out of her face. Also--her eyes are a little squinty and dark here. This is a good example where not adding more light might have hurt a little bit.
3) Natural expressions. I wish they pulled their shirts a little so the shirts didn't frump up as they are. I wish the flowers weren't cut off at the corners like that. If they're part of the scene that you want to include--include them all--it seems odd to place even moderately important / bright / high contrast portions near the edge of the frame--it tends to seem unintended.
4) her hair floofing out front is a little bit distracting. It's precisely the sort of thing she would see in the photo and perhaps wished you would point out on the scene--even if it is windy. It was wise to have her arm cutting across her like that--I mean, it looks a little too stage-y maybe, but helps with showing her figure in a way that she would like, I suspect.
6) having her almost at full side view probably isn't the best idea--combined with her lean it has kind of 'frumped' up her shape from her waist down. I would have had him move in more, and re-positioned myself more to the left so that you aren't seeing the exact side profile of her belly. Note also how your vantage point has a way of flattening her bum area. A slightly different angle (and her re-positioning would help too) and she would have appeared a little more curvy in that area.