Polly: It is isolating to be gifted. The more sensitive the person, then the more it is necessary to have a home that is a haven. Gifted people care deeply about society, but have to self-regulate their interactions because they pick up everything that is going on with everyone and it can be sensory overload. Gifted people generally are independent, so the isolation factor fits that profile, too, because they have an endless list of subjects that they want to pursue, so they are always busy with their own projects. Everything you described is normal for a gifted child. You have to view advice for parents of average IQ children as not necessarily suited for your child's development. We go to the the playground that is least occupied or go to popular playgrounds at off-hours. If you yourself are gifted and a high-sensitivity person, then you are likely super-sensitive to your child's interaction with the other children; that is normal for us. Once, you are comfortable with being perhaps in a smaller group intellectually, you can relax and pursue your child's interests with them while they are young. Gifted people can be very self-motivated and driven from within; they are going somewhere in their life and once they are adults, they might not have as much time for family. Not because they don't care, but because they care very much about the work that they can accomplish.
