You can hardly blame Lady Russell for not knowing this was going to be the outcome of wer interference. And I think her point was a reasonable one, from her perspective. The life of a navy wife was a hard one, and not what Anne had been raised to. What if they got engaged but were not able to marry for years and years because he never managed to gain the advancement and fortune he expected? Should Anne waste her youth, waste the chance to be courted by other men, waiting for her poor sailor, whom she hardly got to see anyway?
And no, Lady Russell did not think he had a steady or trustworthy character. Was she unfair in her assessment of him? Sure she was. She has prejudices very typical of her class. But she did love Anne, and she did have real reasons for concern.
