Headscratchers / The Importance of Being Earnest

• So are we to understand that Cecily just all of a sudden got over the whole "Ernest-only" thing, unlike Gwendolen?
  • No, she regards it as an easy fix: Jack can go ahead with his plan to be re-christened with that name.
    • And Lady Bracknell will just allow him (Algernon, that is, not Jack) to be re-christened? Because this solution didn't work out for Jack in the end - for the very reason that he had already been christened.
• How exactly was Jack claiming to have a younger brother to people like Cecily, who presumably knew he'd been found and adopted as a baby by Thomas Cardew, and therefore wouldn't know any of his blood relatives?