The immoral woman is thrown into a “bed” in the Greek and Aramaic source texts.
If Revelation was originally in Aramaic, then "bed" in Aramaic can also mean "Mortuary Couch". In modern terms we might say "coffin".
However, it doesn’t always mean that the person on it is dead. The same word was also used at Matthew 9:2 to name the sick bed, or stretcher, on which the (very much alive) paralytic man was carried to see Jesus.
So "sick bed", as some translations say, could be correct, but so could “coffin” or “bier” (a bier is a stand on which a corpse, coffin, or casket containing a corpse is placed to be carried to the grave). The context indicates that "coffin/bier" is correct, since the next verse, verse 23 says "I'm also going to put her children to death". Interestingly, the Greek word is also the same one used for a bier.
Otherwise, the idea of an immoral woman being thrown into a bed by Jesus, who then immediately talks about people who were "enjoying sex with her", sounds, well, ... odd to say the least!
Of course, one problem with saying “bier” is that people aren’t familiar with that term these days. So our translation says “stretcher for carrying the dead”.