Like if a Jewish man married a Christian woman, then during the holocaust, what would have happened to her? (Or vice versa)
I'm not familiar with Jewish marriage law and if this was common or not at the time.
I asked a similar question just the other day or so.
Here is /u/commiespaceinvader 's answer:
They had to live with severe discrimination of their partners and things like reduced rations for their partner. Despite some talks about forcibly dissolving these marriages, for fear of the public reaction, the Nazis did not do that.
Lots of other interesting info in that thread.
I recommend reading about the Nuremberg Laws, the racial policy of the Nazis. There are clear definitions of "Jews" that include the spouse of a Jewish man or woman. This also applied to the children of mixed marriages in which one partner was Jewish.
The laws were put into place in 1935 in an attempt to "protect" Aryan bloodlines, thought to be destroyed by mixed marriage. Here is a good overview.