She could sit on the side of the raised bed and reach into the garden. It is important to design the raised bed garden so that she can reach to the center of the bed from either side. If the bed is against the side of a wall or building so she can sit on only one side, then she must be able to reach across the whole bed. Raised bed gardens have many advantages. You can formulate the soil to the needs of the plants that will be grown in the bed.
Different beds can have soil adapted to different plants.
The design of the raised bed can be attractive, adding an architectural element to the landscape. The soil in raised beds often warms more quickly in the spring than traditional garden soil, allowing earlier planting. Of course, raised beds reduce the bending and kneeling required in traditional gardens. You should also contact your local Cooperative Extension Service office for more information. If there are Master Gardeners working with your local Extension Service office, they can also make good recommendations.