Meaning of a sentence

The passage below comes from Jane Eyre by C. Bronte.

(Mr. Rochester)

"What are they, madam?" inquired Mr. Rochester aloud.

(Mary Ingram’s mother)

"I will tell you in your private ear," replied she, wagging her turban three times with portentous significancy.

"But my curiosity will be past its appetite; it craves food now."

"Ask Blanche (Ingram); she is nearer you than I."

On what’s going on : Mary Ingram expressed her scorn against the faults of governesses in presence of Mr. Rochester’s governess Jane. Mary even asked her mother to confirm her statement. So comes the passage.

First, I want to know the two pronouns referents. To me, the former seems to stand for ‘curiosity’ and the latter ‘appetite.’ Am I right?

Second, even if I figured out the referents of the pronouns, its meaning is still in the fog. Still, I made my conjecture that Ingram’s mother do not want to be curious about governesses’ faults because she has no appetite for that curiosity, but instead she now has appetite for food to relieve her hunger.

Last but not least, even if my guesses are right, why the author used future tense(will be past) instead of present tense(is past)? Present seems more suitable.

Thanks a lot.