Were Sarah and Mary discouraged, as opposed to Germanic names?
In trying to impose an ideal germanic mythology in all of society, many NS leaders and party members preferred "germanic" or germanic sounding names like Siegfried, Brunhild, Gerhild etc. Of course, Adolf was extremely popular as well.
A law of 1938 stated that "children of German nationals should generally receive only German first names". "Un-German" names are only to be given for good reasons (like family traditions).
Concerning your examples, as both are listed in this law: Sara(h) would be a very unpopular first name, as all Jews had to use a "distinctly jewish" name, and if they didn't have one, males would have to adopt "Israel" as middle name, females "Sara" and had to use that name and sign with it.
The law also states that names that have been in long standing traditional use are not be defined as "un-German". The law lists "Hans, Joachim, Peter, Julius, Elisabeth, Maria, Sofie, Charlotte" as example.
Source: Richtlinien über die Führung von Vornamen RdErl. d. RMdI. v. 18. 8. 1938