Why don't you ask for your Dom friend's input? I think she could only add to the significance and pride that is involved in your choice to wear this collar. As IDCD said, your collar is specific to you and yours and has a special purpose, so why not highlight that?

lot of Dom men can think they can talk to a girl any way they please with out knowing them gag, sigh, shit like that is one reason why WIITWD has such a bad rep. But, just like you (both) can choose why to use a collar in your relationship, they can choose to call themselves Dom. This is starting to sound like a human rights issue now. sigh.