Ask her to do it! Even if you think she won't do it, it doesn't hurt to ask her to do it anyway. Why aren't you setting expectations for your dog? If she knows how to do it, and you ask her to do it, she should want to do it. What makes you think she won't?
I think you just need to start going for things. My friend is like you when it comes to her horse, she doesn't have faith in her mare to behave/do well and it stops her from doing fun things.
With my dogs and my horse I always look at it as we need to try it. If they're "bad" or do something "wrong" we can always stop, go home, do whatever we need to do to get out of there etc.
I think you need to set yourself up like you would your dog in terms of building confidence. You need to do small things to build your confidence in handling your dog, you need to be put into situations where you won't fail so the more times things go well with you and Inara, the more your confidence raises. Maybe your friends/trainers who know your dog and have faith in your dog could help you find someone situations that you can be put in to help build your confidence too?
I've never really understood people who don't have faith in their dogs/faith in themselves. It's amazing you can simply live with a dog - it's amazing if your dog can sit on command, is house trained, etc. I mean how many dogs do you know who don't even come when called? You should be proud of every little thing you've done with your dog, and be proud of yourself because you've gotten her this far. Even the little things count!
I have no idea if this is remotely helpful but know you can gain confidence in yourself and I hope whatever you end up doing that you are able to gain confidence in yourself and your dog.