Meal planning for mixed needs, any suggestions?

Does anyone have any resources that would help with meal planning for mixed needs? Adult parent is sharing one daily meal with family members. Family members need healthy diet that is somewhat incompatible with the parent’s needs. She does not eat well unless the food is to her taste (meat, carbs), preferred foods (German tastes), tender meat (dental issues), rich (for us to get calories into her), and serious diverticulitis issues. Eating together let’s us monitor/encourage food intake, but we want to eat healthy too.