Concerning that which you write that the parents of the intended (and it would seem the intended as well) do not agree to the observance of Kisui HaRosh:

If this be the case, then if they do not change their minds, G-d forbid, it definitely is not worth pursuing this match. For in addition that this is the "Law of Moshe and Judaism" as mentioned in Shas and Poskim, this itself shows that they wish to begin and establish the match in a manner which is opposite G-d's will. (See also Zohar III, beginning of p. 126a).

There is no need to belabor so fundamental a matter. However, if they change their minds and she will conduct herself as a kosher Jewish daughter, then may it be G-d's will that the match be in a good and auspicious time.

Excerpt from Igros Kodesh, Vol. XI, p. 115