grammar - Usage and origin of "sister" in expressions like "sister company, sister ship, sister site" etc

The term sister is often used figuratively to refer, for instance, to a “sister company” for a company within the same group, or to a “sister site” for sites that belong to the same family. This connotation as explained by the Cambridge Dictionary means:

• belonging to a pair or group of similar and related things, such as businesses, usually owned or operated by the same person or organization:
  
  
  
  
  • our sister company in Australia.
  
  

also, from Collins Dictionary:

• You can use sister to describe something that is of the same type or is connected in some way to another thing you have mentioned.


• ⇒ ...the International Monetary Fund and its sister organisation, the World Bank.
  ⇒ ...Voyager 2 and its sister ship, Voyager 1.

This usage appears to be common with things that are regarded as feminine and are associated, as if by kinship, with other similar things that belong to the same group. An early usage example of this is the "sister" referred to ships:

• the US battleship Missouri and her sister ship, the Wisconsin.

In other instances, the "feminine" issue is less explicit as in the case of internet sites, so I guess this usage has to do with the fact that English is less gender specific when it comes to things or abstract entities.

Questions:

• Does “sister” apply to whatever entity that belongs to the same group irrespective of its real or perceived gender? or could "brother" be used instead?




• Where does this usage come from?