“Do stroke patients have a large risk of vascular dementia?”

My grandmother had a stroke over a year ago, and I'm noticing some symptoms that are a little concerning. Her personality has completely changed (the stroke did take a toll on her mental health, she was diagnosed with clinical depression before it happened and that worsened), but she has been having issues with memory. I know there's a link between vascular dementia and stroke patients. But how big is the risk?