This is wonderful. I absolutely love it!

Very in character. Loved it

That was good. Damn good.

Thanks for the story! Great first effort.
You convey Daria's internal monologue very well; I really like how she uses her sarcasm to try to calm herself about the future.
And go Mr. DeMartino! I think you're keeping both characters well in character while revealing their thoughts.
A couple quibbles: 'churlish' doesn't quite sound right for Mr. D. I don't want to put words in your mouth but to me the word 'brusque' comes to mind.
And I think by '...tax deductible...' you probably mean 'tax deduction' or for a school 'tax credit' but to begin with I don't think public schools pay taxes.
Anyway, please keep writing. I don't think enough writers try to convey Daria's unvoiced thoughts and you do a fine job.
Your avatar is very pretty.