cats play?

Bailey is about 2 1/2 yrs. old. She has very little interest in interacting with me or playing by herself. I've tried catnip bags, feathers, balls, string, you name it. Every once in a while I can get her to chase a little white stuffed mouse, but most of the time I throw it and she just sits and looks at it. She is healthy and a normal weight. She spends a good part of the day on a large screened lanai watching the birds and squirrels, but could this be enough stimulation for her?

Anyone have some thoughts on this?

Some cats don't have the hunting instinct close at hand, if she doesn't want to play, then don't ask her to. Just be sure she gets some sort of exercise, a climbing post, or ramps or something and don't overfeed her so she gets to heavy.