My husband and I met through our daughters. They were best friends. But 2 yrs later they can't stand each other.

This started awhile ago. In fact when we moved into our house. The SD was living with her mother because she and her father had a falling out the year before. Since moving in with her mom, she found out that life is not any better over there than it was with us. She also couldn't "stand to be around her little brothers all day". She is 16yrs old and so is my daughter. Well not too long after she begged to come live with us (which we now know was only because of her boyfriend) we found out she was pregnant. That she had been lying to her father, her mother and I. It had only been 2 weeks since she had been with us and she was 10weeks along. It created a lot of stress in the house. My daughter was stressed about it for selfish reasons of course and my husband was floored. I can't say he handled it well. She has since terminated the pregnancy, but it caused everyone's view of her to be skewed because of the lying.

Things seemed to get better, but then every time my SD messed up or was disrespectful my husband would compare her to my BD. I told him this was wrong and that he was creating resentment. I know this is part of their issues as friends. But now the SD is saying that my daughter is lying about things all the time and my BD is saying the same about the SD. So my husband and I are wondering what to do? We have sat them down and talked about it and things seem to get better. My BD even tried avoiding the SD and her boyfriend but they keep telling my husband that my daughter is flirting with the bf or telling him negative things about the SD to make the bf upset? My daughter is in her own relationship and seems to be very happy and stable with her own bf. I'm not saying she isn't capable of lying because I know she has and to an extreme. But she has also worked very hard over the last 2yrs to remove herself from drama. So I guess what I am asking is for suggestions on how to stop all of this he said she said.