Difficult People

Today I struggle with many emotional conflicts and I am going to post all for the world to see as I just don't feel the need to hold my tongue anymore - bring on the rath.
I have found out that someone who has charge of two lovely young girls, is not treating them as best she could.
I have tried to defend this person to others but I am no longer going to do that, as I have found out certain things about their behavior.
This person in question is my ex sister in law and granted my brother has his faults - I don't lay all the blame on her but come on and step up to the plate.
She is a dancer/actress hollywood actress wanna be stay at home mom which is good if you can swing it or if you stay busy doing things like cleaning and/or cooking for your kids but not her, so she stays home why.?
I swear I think Britney Spears cares for her kids better than this woman does.
I dont get it either because she seems to have come from a normal childhood - her parents are lovely, her siblings are nice also - granted I don't ever see them - nothing personal just distance wise and we don't run in the same circles.
I think her parents though are enjoying their time now and I dont blame them, but that might be why they don't spend alot of time with the kids - I know the girls adore their other grandparents, they always say that.
The girls will innocently mention things to me like : "We don't eat at all on Saturday because there is no food until Sunday's." "Mommy leaves us alone, sometimes overnight we are used to it".
They are 11 and 8, I don't think it is safe to leave them alone.
Also, she and my brother are divorced but my brother continues to live in the same house with them.?
I sense some dysfunctionality there, or is that just me.? I think it is to get a free babysitter, that is why he is allowed to live there.
The house is always dirty, cluttered and the girls look like rag a muffins which is a shame because they are absolutely gorgeous, so different in their own way - the older one is pretty in a nice simple way but pretty pretty and the younger one is just strikingly pretty and they will only get better with age.
I never dare say boo to her or my mother for fear that we won't be able to see these lovelies anymore but I am getting less and less tolerant of this behavior and I am thinking something needs to be done.
I could go on for alot longer but I think I made my point, I just try to remain positive and thankful that the girls have a good influence like my parents in their lives, I think it does good for both my parents and my nieces.
Thanks for letting me vent..
Peace J