Why is she avoiding me instead of being direct?

A month ago I asked my friend out on a date. She said no, but would still like to be friends. I was cool with that. I’ve seen her like 4-5 times since asking her out. At first she was still cordial; friendly, said hi, smiled, and waved. However, when I last saw her a couple days ago, she just avoided me and ignored me the whole time. I said hi to her twice, she just frowned and turned away. Then she was invested in talking to one of our mutual friends for the rest of the time the group was hanging out. He paid for her meal and walked her to her car. She could’ve just told me she liked him. Sure I would’ve been hurt, but at least I wouldn’t have been confused by her avoidant behavior.

Why is she avoiding me instead of being direct?
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