Hi katlynn:
I’m going to assume that you had V4 selected in your Scene Tab when you loaded the clothing. That should “attach” the clothing to her. However, I’ve found sometimes clothing that “looks” as though it’s attached properly really isn’t, so what I usually do is select the piece of clothing in the Scene Tab, and then in the Parameters Tab under the Misc section, select the “Fit To” option, and it will show a small pop-up list of objects you can fit the piece of clothing to. Select Victoria 4.2, and the clothing will stick to V4 when you pose her.