Her motives contradict her actions. She returned to Lindon, but we don't even really know why or for what reason. Look at the scene where she gets the ultimatum from her company, she doesn't go back willingly. This may imply that she can't do it alone, but she literally explains to Elrond that she's determined to go back alone. My argument that her decision to return does not make sense based on what we've seen established in her journey. She goes back, but there is nothing that implies she had to because she needed support of her troops, because the show failed to establish that connection. It's actually left completely ambiguous, and only implies she has to go back because of the other Elves. But there are other factors as well, like her seeking Elrond to have an audience with the King to show him Sauron's mark.
And what exactly did her returning to Lindon actually serve to make her decide she will go it alone, and not when she's already in the North?
Well, the writers needed her to have some dialogue with Elrond and set up to place her in the middle of the ocean, is what. These events are all written to have her placed in a situation that takes her to Numenor.