After you have set up your simulation in the Cloth Room, proceed to Cloth Objects section and clothify the sweater through the Clothify... Button.  The screencap below identifies the buttons you should be clicking.

After the clothing item is selected, exit the Clothify panel and proceed to the Collide Against... button.  With the Cloth Collision Objects panel open, click on the Add/Remove button to select the collision object, in this case, it's the LaFemme2 Figure.  The screencap below will show what to expect when you open each panel.

This is how you create a fitting simulation for both the figure and clothing.  If you are following any tutorial video on the Cloth Room, this is exactly the procedure you should be following to get a successful simulation.  

Please acknowledge that this is what you are doing.  I agree with RedPhantom, there appears to be no collision set for either the sweater or the dress.  That is why the clothing is not fitting during the simulations.  My suggestion is to attempt to master the basics first before you begin introducing poses and morphs; learn to simulate a simple fit.  Once you have mastered running a successful cloth simulation with various clothes items, experiment and refine your procedures.