Forget roses--most women would rather have a Fitbit. Not the watch--just the slim band. Try the Alta, and remember: you can change colors and sizes. Don't get small if your gf isn't small :-)
The website is HERE. As of February 7 2017, Fitbit is offering 25% off and free 2-day shipping for Valentine's Day.
Disclosure: I own stock in Fitbit, but my positions may change at any time. There's a lot of competition in the fitness band and watch space--I just ordered myself a Garmin Forerunner 35, but that's because I had a coupon. The watch I ordered--not to be confused with the "cuter" band--is more expensive, but it has GPS. I haven't worn a watch in many years, but I couldn't resist trying one with a GPS and heart and sleep monitor. I'm not looking forward to adjusting to what must be a tight wrist fit to get all that data, but the unexpected coupon persuaded me to take a leap.
Fitbit seems to be more popular because it has an active online community and allows more customization--I couldn't choose any colors or sizes for the Forerunner watch, and this particular product doesn't sync with an app (Connect IQ) allowing customization. If you're looking for a similar Fitbit product, check out the Blaze.
Disclosure: I am/we are long FIT.