Q. Does in the above case (A prior already married couple [to each other] that is now converting and going to the chupa on the same day as the tevila) the Giyores kallah wear white since she is like newborn? Is there a Badekn ceremony? Does she make the seven hakofos under the chupa?
 
A. In question 692 on this forum we wrote in regards to differences between the minhogim and traditions of a first and a subsequent marriage ceremony; “There are different traditions as to the wedding dress of the bride. Horav Shlomo Miller indicated that she could dress in white, but not with the prominence, length and extent accustomed in a first wedding. The Chosson wears a Kit’l if that is his family tradition. (Nitey Gavriel ibid. 9, see also Hanisuin Kehilchoson 17: 20.)
There are also different traditions in regards to the Badeken or the chosson covering the bride with a veil ceremony. Some avoid it altogether, it is done by others such as the accompanying women doing it instead, or it is done by the chosson under the chupah. (ibid.19.)
Horav Shlomo Miller’s Shlit’a opinion is that the same would apply to a prior married (to each other) couple that now converted and is getting married. There is also no need for the seven hakafos under the chupa.
 
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a