Accept that your child may not be as popular as you want. If your child is lonely, then look for ways to help her make friends, but if your child is content being on her own, then accept that. Being popular is not the same as having social skills. As a homeschooling parent you may find yourself being pestered about whether or not your children have social skills. Do not let yourself start thinking that your child needs to be popular with other kids his or her own age in order to prove to these other parents that you are doing the right thing.
Social skills are different than popularity.
Social skills involve knowing how to carry on a conversation, put up with people one doesn't like, and make patient suggestions to others. Ironically, schools may be the hardest place to really learn these things because one is locked up all day with other people who haven't yet learned those skills either. Allowing your child opportunities to be around people of all ages is probably much more beneficial. Let your child be herself. Teach her to love that self and to be compassionate to others.