My DH and I have been married for only 5 mos. I have 3 wonderful kids and he has 2 children of his own. We have been living together for almost a year now, but the jealousy between our two youngest daughters is getting out of control. His is 6 years old and mine is 4. The most recent fight has been one over the SD's birthday party coming up soon. She has told my daughter that she cannot come to her party because she doesn't like her. I know it is childish for me to get involved, but it is hard for me to see my baby get her feelings hurt...