In OP its stated that she "rounded" 1b. so if the obstruction occured past 1b how is it that she isnt protected to go to 2b?

She can not be called out between the bases where the obstruction occurs (in this case 1st and 2nd) but that does not mean she is awarded 2nd base...... She can be returned to first base if you feel that absent the obstruction she would not have made it to 2nd safely.

In other words, she is "awarded" or "protected to" the base you feel she would have attained absent the obstruction.
In addition, she can not be called out between the bases.
So if you don't feel she would have made 2nd base safely and she gets tagged out between 1st and 2nd - you can't call her out, but you can't give her second so.............:D

She is. What's your question?

FWIW: I read the question as to why she was placed back at 1B and not placed on 2nd base....

Worded funny if that's what they meant, but I guess I can see that.