I think your daughter is pretty similar to my two guys. They're both somewhat limited in their 'fear' reflex, at least for most things (my older one is pretty clingy when he thinks we're going to leave him somewhere).
There are basically two sides of this. On the one hand, being willing to try new things and do all sorts of physical activities is great. On the other hand, not jumping from unsafe heights would be nice, too.
What we did with our boys is:
- Talk to them about why certain things are dangerous. Walking on the street is dangerous because of cars. Jumping from tall buildings is dangerous because of broken limbs. Etc.
- Gave them guidelines for avoiding dangerous situations. They have to hold our hands while crossing a street. They should stop before an alley or driveway (or street) and wait for us to catch up. Certain playground things are for up-only (like some ladders that are hard to safely go down).
- Carefully monitored them and reinforced the guidelines, and the reasons, until we were confident they understood them.
My three and a half year old I'm entirely confident walking down a busy street's sidewalk without holding onto him, regardless of his mood. He is very careful (but adventurous) on the playground sets. He tells me when other kids do things they shouldn't. He understands, internally, why it's not safe to do these things.
Now, is he perfect? Will he never ever make a mistake? No. But he understands why he should be careful, and almost always is - and I'm there to make sure nothing dangerous can happen if he does forget.
Ultimately, teaching your child why, not what, is the best thing you can do for them. Teach them what, you know what they'll do when you're there. Teach them why, you know what they'll do when you're not.