There isn't an English word for "cousin", "aunt", or "uncle"? How did they refer to their not-quite-immediate family members before these foreign words were inserted in the language?
Actually, it's not quite the same -- in German, the word Säugling (literally: a "suck-ling", or one that sucks or nurses) still exists, but Baby is much more common. (While in English, I don't think any form of the former relationship names has survived.)
If you want to sound like a native speaker, don't shy away from well-established loanwords.
Similarly, don't try to use Schreibstube instead of Büro or Gesichtserker instead of Nase etc. I'm not even sure there are native words for Straße or Fenster.
Use Baby. Use Party. Use Handy.
Perhaps you don't have to say Weekend.