Now you'll need that utility to unide the scaling dials.  It's just a script, I'm sure there is a free one.  I'll see if I can find a link to it.  If you then select the "chest" body part of the tutu, you can dial in the 114% (the actual freak morphs have the chest dialed to 120%.  70% dial is 114%  - 20*.7=14).  Once you dial in that chest scale, the dress will fit.