It already has the Array in the Base class, I was just trying to figure out how to add to that array in the child classes.
I seem to have figured it out.
Originally I was just trying to access Fragments like
Fragments.Add(newfragment)
and it was erroring out on compile.
I did this and it now works as expected.
UArcItemFragment* TextFrag = Fragments.Add_GetRef(NewObject<UArcItemFragment_Text>(UArcItemFragment_Text::StaticClass()));