I think she sounds depressed and suicidal. She tried to pry the stickers off because all the work that had gone into the boys and their sports was over. She felt completely defeated. If the boys were wanting to live with their dad, that would be the kind of blow that would drive a mom over the edge. An already depressed mom might also be very upset if the boys expressed that their dad's house was bigger or whatever. The boys were freshmen or sophomores, I believe. Difficult age, Dad was probably the Fun Parent.
I think this will turn out to be self-harm too, although the iPad is the one clue that makes it only slight less dire. If it's true, though, she must have had some means of doing it. If she wanted the iPad to hold a suicide note, she ought to have left it in the car. The only means of suicide in that area, it would seem, would be a pond - so???
If she did in fact head for public transport, wouldn't the boys have noticed if she took a back pack? If she planned to leave for parts unknown, wouldn't she have packed a bag or something?