Yes.  Yes it is.
It's the most evil part of the story, but it's honestly just a part of what these poor sisters go through.  They go through plenty of marginally less evil things as well.

Man, that's pretty rough too.  But that also sounds like bad decisions all around.  

I think she will.  Hopefully that part will work out.  Something has to work out for these two eventually.  It's some law of probability, I think.  Odds are something HAS to go right EVENTUALLY.