<human>: Give me a shortened version of the text

We adopted a seven month old Australian Shepherd from the shelter about a week ago. They had her listed as "PG-13 Skittish", and I wouldn't call her all that skittish. She's very meek and submissive, though very eager to please and smart as a whip. Her submissive behavior isn't what is causing a problem though, since we're working on building her trust and confidence with us and she's taking right to it.

Random things scare her--not noises, but objects. These seem to change every day. She'll be terrified of something one day and fine with it the next. I suspect this is just because she's getting used to her new home and to us, so the little things, I'm not worried about. She'll get over her terror of the dog-poop-bag-trashcan, since she's constantly exposed to it.

The other day, it was pouring when it was time for our morning walk, so I broke out the umbrella. The sound of the rain on it terrified her briefly, but she got over that after I showed her that it was okay, and we went on our walk. When we came back, however, I went to close the umbrella. NOPE. She FLIPPED OUT and pulled out of her harness (I tightened it afterward), then ran out into the rain and lay in the grass, crawling to me on her belly with some serious reservations. Luckily, she doesn't run from me and so she waited for me to come pick her soaking wet ass up and carry her into the house.

I have a few questions. 

1.) Is this just a symptom of a fear stage? Is there anything I can do to help her along during this? 

2.) How can I get her not-afraid of the umbrella, which is huge and makes scary sounds?

Other than her random little fears and her occasional forrays into/near the litter boxes, she is the absolute perfect pup so far, and as her confidence grows, she gets even better! I want her to be confident on rainy walks, so how can I get her used to the umbrella without scarring her forever? We do clicker train.
<bot>: Aussie in a possible fear stage terrified of umbrellas. How can I work on this without making it a phobia?