Yes, someone with BPD can be a good parent, and they can quite easily be effective and nurturing as parents, the symptoms of BPD can be very intense which may sometimes lead them to treating their children the way they should not be treated and the children will be damaged because of these tendencies. Being a good parent may require hard work even for people who do have BPD, which means that someone who does will likely have to work harder at making it work, and they should probably learn the best ways to manage stress and negativity in their life.