Go Kayaking with her. A camera and lenses and you could do wildlife or macro photography or fishing on your trips. Great Exercise and connection with nature. If you get something like a DJI Mini drone you can capture something people rarely see. Maybe you could even start a youtube channel with all the unique footage. Which would require video editing and photoshop skills. Not even that expensive:

Mirrorless camera $500

Drone $400

Two kayaks ~$1000