Man... reading this made me think about my own sister sooooo much. And the brothers of several friends.
Classic 'younger sibling' syndrome.
The oldest always has to figure things out for the first time and gets to make all the hard choices without any real help. He/she then has to explore the full scope of consequence for the decisions he/she makes. Meaning, that they are forced to wonder about what would happen if they fuck up, and how they could fuck up and what would happen if they make the right choice and what the hell the right choice is.
The oldest also has to be a role model for the youngest, so typically tends to have more responsibility and more weight on the decisions. So all of this makes for a very responsible human being (at times too responsible, but that's a whole thread in and of its self).
The youngest however has the benefit of more experianced parents and an older sibling from whom he/she can 'copy' decisions. However, as it is with copying, they don't really know the reason for your decision and often don't understand the full scope of the decision. They just do what you did and move on. This is all nice and easy, but leads to taking decisions a bit for granted.
So where you and I probably have a little voice in the back of our heads saying "Hey, you need to stop gaming and start doing that homework or... ::little voice shows us picture of self as a bum::" our younger siblings probably have a voice saying: "Hey, you need to stop gaming and start doing that homework, cause that's what you're supposed to do".
You can see how the former is more convincing than the later?
So in short, I agree with everyone else. Don't shield her, don't help her in any way. She's in a new situation now, let her work it out for herself. Don't protect her or make decisions for her.
That's my €0.02 of amateur psychology anyway.
EDIT: You know, it also made me think about this quote from Douglas Adams:
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."
