Companion Care Needed

We are looking for a senior care provider with experience. The senior handles her own self care and keeps a very neat home. She is intelligent, highly educated, and conversational. She has some short-term memory loss, and recently lost her husband. Our care concerns are mainly companionship and dinner preparation. They may also include light housekeeping (though she has a bi-weekly cleaning lady), possible help staying physically active, some errands / shopping, transportation. When one of us comes to visit, we usually will not need help, and hope an arrangement can be made.