It's not a dipthong, it's an umlaut.
www.answers.com/umlautwww.answers.com/dipthong
I'm not exactly sure how the ä is pronounced, but don't forget that in
German the 'e' at the end will be pronounced and the 'th' will be pronounced 't'. My best bet is that Käthe is pronounced KAY-ta. I could be completely wrong but that's what I can guess from my knowledge of
German linguistics.
:-)
♦ Chrisell ♦
All we have to decide is what to do with the time that is given us. - J.R.R. Tolkien.