This is a little bit of selfishness on Usagi’s part, which is realistic- she’s a teenage girl, not an endless font of sainthood.
But it’s also one of the good things about Usagi- she sees exceptional women, and rather than being resentful, she admires them and wants to learn from them. All the others look at Ami and all they can do is resent her. But Usagi sees her intelligence and wants to be her friend and learn from her. She doesn’t feel competitive, she admires Ami for who she is and wants to be like her. She sees other women as allies, not enemies, from the beginning.