There is no way to know for absolute that your kitten won't run away, but there are ways to help her find her way back. It may sound odd, but if you but a little butter on her paws, they will be able to find their way back by the scent. Make sure that she has her collar so that if she does get lost, she can be brought happily back to you. Once she builds up her confidence, it should all be good. :) Try playing with her a bit outside. :)

In my experience, I have had cats that were perfectly content staying inside, and then I had cats that were dying to get outside every chence they could. I love cats- I have 5. But the way I see it, if you preserve it's life by keeping it inside, but its spent dying to get outside the whole time, what's the point?

I would keep her inside until she's about 2 yrs. Old, and then start letting her out. Kittens are too curious and will approach just about anybody. Give her a chance to grow up and fully mature. If she's still dying to get out at that point (and she's been spayed/neutered, with all shots) I say let her out. Also, have you considered having her microchipped? Its really not very expensive, and it can be done at the same time as the spay or neuter.

Of course, I live in the country. If you live in the city, definitely don't let your cat out.

I would try a small shock collar

No problem, wish they did the same for my partner too. Lol