All women want to feel feminine and attractive, and plus-sized girls are no different.
Some girls may begin to feel that you're "hiding" them if you don't introduce them after a reasonable period.
During activities with friends and family, keep the conversation general and involve your girl as much as possible so that she feels included. Instruct less-than-tactful family members not to mention your girl's size or eating habits.
Enjoy problem-free dates with the special plus-sized girl in your life by being prepared. Don't make reservations at a restaurant where you know the chairs are small or take her to an amusement park where she'll have to squeeze into a rollercoaster seat. Try to take her to places where there will be people of all shapes and sizes; for example, go to the mall or an outdoor festival.
Don't plan anything active, such as hiking, unless she suggests it; she may be embarrassed by being out of shape or unable to keep up.
Keep the conversation light and positive and remember to tell her she looks lovely.