Jehovah's Witnesses feel it is important to identify and differentiate between fornication and adultery

I submit that it does not matter.

Jesus goes further in identifying adultery: "You have heard that it was said to those of old, ‘You shall not commit adultery.’ But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart. If your right eye causes you to sin, pluck it out and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into hell. And if your right hand causes you to sin, cut it off and cast it from you; for it is more profitable for you that one of your members perish, than for your whole body to be cast into Gehenna." (Matthew 5:27-30)

It is important to remember that, "For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it." (James 2:10) That is why I feel the distinction between fornication and adultery is not something I would ask about. "For all have sinned" and the "wages of sin is death". (Romans 3:23; 6:23) All we can ever earn for ourselves is death.

But the good news is that Jesus has received that wage for us. “He was delivered over to death for our sins and was raised to life for our justification.” (Romans 4:25) “Now to the one who works, his wages are not counted as a gift but as his due.” (Romans 4:4)

See what Jesus says to woman that He Himself identifies as adulterous: "“If you knew the gift of God, and who it is who says to you, ‘Give Me a drink,’ you would have asked Him, and He would have given you living water.” John 4:10

Yes, fornication or adultery, "the wages of sin is death...

but the free gift of God is eternal life in Christ Jesus our Lord.” (Romans 6:23)