I don't think Padma really believes she's capable of all of it. I think she believes she OUGHT to be, and that admitting she's not would cause Sandoval to scorn her, which she can't bear.

Draco's from an old pureblood family, one of the most influential families in the Protectorate -- he's really got nothing to prove. Padma, well, her family's certainly pure but they're in a different category, she can't afford to slack off, or at least that's what she thinks.

I wonder if she knows what she actually wants?