My question is, is this literal, as in, she's physically standing behind me, or is it figurative, as in she's being supportive of me?
Standing physically behind.
Stuenen is the verb "to support".
So figurative would probably be
Steunt zij me?
At least in my idiolect it's both, not sure about standard dutch
Why present simple is not correct? So: "Does she stay behind me?" was counted as incorrect answer
Why isn't it " achter mij " ?
Couldn't "after" also be a synonym of some sort for "behind". I feel that it makes sense in a supermarket queue, for example, to say if someone is after you, they're behind you in line.
(this is referring to the translate to English exercise)
Is me and mij interchangeable?
Ja, ze staat achter je en ze heeft een mes.