This is an interesting question. Of course when we love a cat, we want to think she is happy, contented, and feels safe in our home and in our presence. But how can you tell when your cat is happy? As they say, “Cats can’t laugh,” but they can purr.
Now, not all purring is a sign of happiness. Cats also 
purr when they’re in distress. They purr in order to comfort themselves. But seasoned cat owners and those who pay close attention know when their cat’s purr is a happy purr.
A cat at play certainly appears to be happy. The sillier Olivia gets, the happier she seems. When your cat is on your lap making biscuits and purring—oh yes, that’s a happy cat. Sometimes just a look your cat gives you, like from upside down while lying on her back on the floor—seems like a happy and contented cat.
Here’s a fun article outlining ways to tell if your cat is happy or not. Enjoy: https://curiositytrained.com/can-cats-laugh/
