I think the family likes Anna just fine. However when Anna first became a Duggar, the older girls could not spend a lot of time with her. Firstly, they were too busy being buddies, teachers, cooks, tile layers etc. Secondly, this crowd seems to prefer to keep the married people separated from the unmarried females. Would hate for certain things to be discussed you know.
and now, the older girls and Anna are all busy taking care of their own families to hang out.
Regarding Anna and divorce/remarriage. Legally she could of course. Practically, not all that many men wanting to