Original sentence: Recent events in the series include Supergirl being covertly watched by Lex Luthor, the discovery that she is resistant to synthetic Kryptonite and various characters implying that she may be stronger than the Man of Steel himself
Edited sentence: Besides, Superman is actually far stronger than Supergirl and Superboy, and is shown to get even stronger as he grows old.But as Wally West said on her, being a teenager made her more eager to impress her cousin, seeking for acceptance from her new "family", the metahuman community of Earth.Eager to "grow" as a more complete hero, in a short time span she had improved with the Amazons of Themiscira her combat skills, honing her body and her mind.In terms of power, she is the female version of Superboy.It's as logical as thinking that a teenage girl is stronger than a fully grown man.Recent events in the series include Supergirl being covertly watched by Lex Luthor, and the discovery that she is resistant to synthetic Kryptonite.She now able to take over with a little effort her "half-cousin" Superboy, adding knowledge to muscles.So she may be pushing herself more than Superboy himself, always puting in every trial more raw power than the more expert Superman needs to use for the same feat.Though some fans believe that it's implied that Supergirl is a little stronger than the Man of Steel himself, it's illogical and not true