Our Toro actually came with either a 3 year or 5 year one start pull guarantee. 10 years later it still starts with one good pull. The model level above the one Pete linked comes with this guarantee as well.
The self paced mowers are easy as can be when it comes to pushing, the speed to goes at is based on how hard you push on the handle, and it doesn't take much force at all to push it down. My son 9 yr old son can push it around, so unless your GF is in a wheel chair, she shouldn't have problems. And dude, you get a big high five if you get your GF to mow your lawn for you, lol.