It’s an upholstered chair with a seat cushion . I purchased a product on Amazon . I put a sheet under the cushion and one on top of the cusion . This way if she falls asleep on it watching tv, she doesn’t slide off . It’s worth a try !
Several have been mentioned The rubbery shelf liner should do a good job helping to prevent sliding. There are also gel pieces that are designed for this. They sorta feel like the "sticky" lint rollers that can be rinsed off. If the wheel chair has a tilt back that might be another way to prevent sliding. As the back is tilted back it becomes more difficult to slide out. If there are cushions on the chair alternate them if possible the cushion gets compressed on one side so sliding is more apt to happen.
The rubbery shelf liner should do a good job helping to prevent sliding.
There are also gel pieces that are designed for this. They sorta feel like the "sticky" lint rollers that can be rinsed off.
If the wheel chair has a tilt back that might be another way to prevent sliding. As the back is tilted back it becomes more difficult to slide out.
If there are cushions on the chair alternate them if possible the cushion gets compressed on one side so sliding is more apt to happen.