I second Sue’s suggestion. It sounds to me that you have a client with diabetes and cardiovascular disease. On the assumption that she is also rather deconditioned, maybe overweight, you have a client who would be in the ‘high risk’ category.
She has been cleared for activity; but that only means that she should exercise at the level appropriate for her conditioning. If you want to do outdoor activities, take a light resistance band and use breaks in the walking for some light work. Monitor her very closely.
If in doubt, refer back to her physician for more specific recommendations.