Given Matrilineality, would you accept a daughter dating a Gentile?
Dating a Jew would always be preferrable over dating a non-Jew, but I could think of cases where it would not be extremely problematic for a daughter to date a non-Jewish man as it would be for a son to date a non-Jewish woman, yes. I don't think any of this is about "accepting", though: once grown up, children are autonomous people who make their own decisions and as a parent you will have to "accept" that, whether you like their decisions or not.
That raises a difficult question of: at what point does desire to preserve culture and traditions become a form of racism? I am not accusing you of being racist, but it is a gray area.
DavidB,
I am curious of your opinion on this as well.
I don't really know, but I'm very reluctant in calling people's dating preferences racist because I think it is legitimate for people to select their partners on about every criterion they want to use for any or no reason.