Not just counting the human crew members, how many survivors are there at the end of the movie "Alien"?

When we look at all the survivors of the Nostromo we have Elen Ripley as the only surviving crew member, But she is not alone after killing the Alien at the end of the movie.

The other survivor is the cat Jonesy.

So if we count all the survivors and not just the human crew members the number of survivors is two.

Jonesy, also referred as Jones, was a cat, more specifically a Ginger Tom, kept aboard the USCSS Nostromo as Ellen Ripley's pet. While the cat's official purpose was to control rodents aboard the ship, it also served as a source of relaxation and entertainment for the crew.

Jonesy was attacked by the Alien when Ripley left him in his cage, but the Alien left him alone as Jonesy was apparently of little interest to the creature and he survived the incident unscathed. He was put in cryo-sleep after escaping the Nostromo with Ripley.

Ripley and Jonesy remained in cryostasis for 57 years. The salvage crew that picked them up initially thought the unusual readings from the cryotube was that of an alien life form, but visual inspection revealed to them that they were simply reading the human and feline sets of DNA as one organism. After their recovery, they were reunited in the hospital of Gateway Station by Carter Burke.

Alien was a movie by Ridley Scott and revolutionised sci-fi and horror.