Answer:
By saying this Lady Bracknell is making a point that it is useless, time and money wasting for Jack and Algernon to be baptized at such age.
Step-by-step explanation:
The Importance of Being Ernest is a play written by Oscar Wilde.
In Act 3, of the play, after Lady Bracknell gets to know that Jack and Algernon were lying about their identity to Gwendolen and Cecily, refuses Jack's marriage with Gwendolen.
At that time Dr. Chasubel arrives, prepared for christenings. Surprised to hear that Jack and Algernon were thinking about christening, she asks, "Is that not somewhat premature?" meaning that is it not too early for them to be baptized. By saying this she is making a point that it is useless, and time and money wasting to do such thing.