Deadly Women (2005)

Rachel Wade and Sarah Luderman engage in an online battle for the affections of a boy and the battle enters the real world. When Sarah takes one risk too many by confronting Rachel at a house after humiliating her online, Rachel is armed with a knife and uses it to effectively kill Sarah. Caroline Young was so upset at the thought of losing her grandson to his biological father, she stabs both her grand-kids (ages 6 and 4) and also stabs herself (but survives) and all of this is while her daughter and the kids' mother is watching. Elizabeth Duncan had only one man who always stuck by her - her son Frank. So when Frank marries his pregnant girlfriend (who helped nurse Elizabeth back to health after attempting suicide) in a private ceremony, Elizabeth taunts them with phone calls and hires two amateur criminals to kidnap and kill Frank's pregnant wife and their unborn child.