BOXBORO — A 61-year-old Massachusetts woman has been charged with stabbing her adult son.The Lowell Sun reports that the 22-year-old son reported the attack that allegedly happened inside the Boxborough home they share shortly after midnight on Nov. 8.Boxborough police say 61-year-old Karin Evans told them she stabbed her son in self-defense because he attacked her with a pair of tin shears.