What things can I do for a nursing home parent to make them happy?

Take them to music activities; it's a very uplifting form of therapy.

Does your parent enjoy arts and crafts activities, and are they offered at the NH? Arts is also another therapeutic activity.

What does your parent enjoy doing, especially before living at the NH?

If their diet allows it, I would take them their favorite treats and beverages, old photo albums, make her a scrap book of things she enjoys, decorate her room with lovely items of things she likes if the facility allows it, send her lovely cards with nice personal messages, see if the facility has pet therapy so she can cuddle with a dog or cat, rub her hands and arms with a nice smelling lotion, brush her hair, take some children to visit if you know any.

Of course, it depends on her personality and if she has any mental decline as to what types of things she would really enjoy. Some residents in a nursing home may not be up to so much activity. You should know what she can handle.

Are the grounds outside the home landscaped? I often wheel my mom outside ( bundled in a jacket in the 90 degree heat mind you) to look at the birds and flowers.

Keep your visits short.