Originally posted by CaptainStoic
About the same amount of things that Diana could do to her. Experience will play a huge part in Supergirls defeat. Besides that she's just plain out more powerful than Supergirl is.
Ms. Marvel possesses a wide array of superhuman powers. Initially, they include superhuman strength, endurance, formidable resistance to physical injury, the ability to fly, energy absorption (including sound waves), energy projection, and a limited precognitive "seventh sense".
Ms. Marvel temporarily re-powered into her Binary form by the Collective. From New Avengers #17.
Art by Mike Deodato.As Binary, she could tap the energy of a "white hole", allowing her to manipulate stellar (or "cosmic"

energies, which she could radiate as heat, light, and the rest of the electromagnetic spectrum as well as gravity fields, on a scale with a Herald of Galactus. After a massive expenditure of stellar energies, she would revert to human form and needed to rest in that state. She possessed strength far greater than her original level, and when flying could shunt herself to hyperspace to exceed light speed, and could exist in the vacuum of space unprotected. Binary managed to force open a Shi'ar Stargate, a feat only Firestar, Thor, Nova and hosts of the Phoenix Force have been shown to accomplish.
After Carol's link to the white hole from which she drew her powers was severed, she lost the bulk of her cosmic powers, but still retained her potential for energy manipulation in addition to her original powers of superhuman strength, injury resistance, and flight. Ms. Marvel can discharge explosive blasts of radiant energy, which she fires from her fingertips. These blasts are comparable in force to her fellow Avenger Iron Man's repulsor rays. She also demonstrates the ability to absorb other forms of energy, such as electricity, to further magnify her strength and energy projection, up to the force of an exploding nuclear weapon.. When sufficiently augmented, she can withstand the pressure from a 92-ton weight, and strike with a similar level of force. Hank Pym theorized that this likely was not her limit. Carol can absorb magical energy, as when she helped Stephen Strange defeat the mystic menace Sir Warren Traveler.
Well she seems pretty powerful... but not powerful enough to beat supergirl... Supergirl has busted moons, taken sun level explosions to the face, etc... some might argue that her performance in the legion gave birth to feats comparable to supermans.