Simple answer, all clothing is designed for a specific figure and will only work for that figure in poser. Any extra figures you buy cannot use clothing for other figures but must use clothing designed for that figure.

It is possible to convert clothing from one figure to another, Poser has the fitting room, there are tutorials on this around, and Evilinnocence has a utility program, crossdresser, that can also be used. The program is free but you have to buy a licence for the figure you want to convert to, these cost about 10usd. You can buy the licence for LaFemme here at Rendo, the program and other licences are available at Evilinnocences site. I personally rarely convert clothing as for me at least conversions often don't work as well as the original.

One further point, if you downloaded the free content that now comes with poser 11.2 (you need to enter your serial number on the same page from which you downloaded poser 11.2) you get Dawn, and other Hivewire figures free so don't need to buy them, together with some clothing for Dawn.