This is the animated Terra from Teen Titans. The costume's not too difficult.
Black long sleeve crop top and canary bike pant from nydancewear.com.
Military style belt from military supply store.
The Circle T was created and printed using the computer.

Here's another comparison.

The animated Terra is a bit different from the comic book Terra.
In the comic book, she was a traitor from the beginning (& Slade's lover!), and then died,
whereas in the TV show she wasn't really evil, just "confused" and then encased in rock.
(And in the comic book she was brought back as an alternate reality version of Terra, then
it was revealed she was the real Terra, but she doesn't know that. Not too confusing!)
One thing I do know - the animated Terra is a lot cuter than the comic version!

Okay, the comic Terra is pretty cute in that 2nd pic, but that costume? Blah!
And what's with those boots?

Who knows if we'll see the animated Terra again. She's not in the next 13 episodes.,
although she is in the Teen Titans Go! comic book.