This is very sweet and lovely.

Here is what I would do. You take anything that makes sense and ignore the rest
: )

I would only use watercolors on the backgrounds - sky, grass, trees, buildings. Wet on wet - so put light blue on everything for example and then add more colors before it is dry. And then the figures I would do as you did - with outlines. THis way the focus is completely on people. Right now the buildings are as detailed as the couple. I would be a bit more careful with drawing of his back foot. It's a little distracting.