I am having trouble getting Cass to join me.I have gone through all dialog options and there is nothing telling her to join me.Even when doing the Crimson Caravan quest that involves them buying Cass's Caravan out I can't recruit her.The option to buy her out never even comes up.

You'll probably need...

• (Barter 50) Pay her an extra 750 caps.
  
• (Barter 75) Challenge her to a drinking contest and obtain 12 whiskeys.
  
• (Speech 50) Either clear the roads so Jackson will let her leave by getting and completing the quest Can You Find it in Your Heart?, or kill Jackson quietly with no one seeing.
  
• (Speech 75) Just convince her she should sell.

Or follow the steps http://fallout.wikia.com/wiki/Heartache_by_the_Number

Figured it out, it was a minor glitch in the quest.