Asking fiancee to wear this dress for the wedding reception

Hi, my name is jacob nguyen and I am a vietnamese american man and I am getting married in december to my fiancee in vietnam. I want to ask her to wear a chinese cheongsam dress which in vietnamese is an ao xuong xam for the wedding reception. I saw my cousin wore one for her wedding a few years and I kinda want my bride to wear one. She would be already wearing an traditional ao dai dress for the ceremony so I just want her to change things up and wear this for the wedding reception. Should I ask her ? Would she be ok with wearing it if she is vietnamese ?

Simply ask her.She will either say yes or no.  So 50% chance either way.
How can we tell if she is okay with wearing it or whether she will want too.

My wife wore 3 different dresses at our reception, so you shouldn't have a problem with only 2

Some Vietnamese women like to wear a cheong sam. My wife used to wear one to work when I first met her. Some other Vietnamese may not like the idea and would prefer to wear an ao dai. As suggested already, just ask your fiancee. She may even prefer to wear Western dress.