It was done with StackOverflow (now Stack Overflow En Espanol exists, as Stack Overflow Em Portugues). Is it still considered an accepted practice or will it likely be closed (e.g. by moderation) if I create a new proposal in a different language (e.g. if I try to create a spanish mirror por Parenting or Pets)?
Is it still an accepted practice to create a different language version for an existing site?
Unfortunately, we are not currently accepting proposals for non-English sites.
See Internationalization 'State of the Stack'
This also applies to non-programming sites.
Internationalization 'State of the Stack': Stack Exchange Edition