Automatic Wheelchair Brakes?

Until this time (when I have taken her home with me before), she always remembered. This time, not always. I have been making sure to be with her when she transfers. Doesn't it seems like the wheelchair companies would jump on a chance to sell an add on device for just this situation because I am sure it must be a common problem. She doesn't use the footrests and uses her good leg (Stroke affected left side) to scoot around. Thanks!

Is she attempting to transfer by herself? Or is someone with her?
If someone is with her it should be up to that person to make sure that brakes are on.
If she is in a wheelchair and transferring alone I would be concerned with the dementia that at some point she will forget how or what to do next.
And does she use the foot rest? If so moving that out of the way so she can safely stand is important, or does she not use them?