Dependency

After saving Austin in the quest “Hole in the Wall”. Talk to Tina de Luca and learn about her brother's worsening addiction. If she doesn't give you this quest, try talking again to her after a week. Once you got this quest started, go to the clinic and talk to Rachel. Next, convince Bobby to seek treatment. Once done, talk to Tina again to update the quest.

(At this point, you can use a speech check to supposedly recruit her as a settler. However, there is a known bug about this that she won't even leave the vault even if her dialogue states that she'll finally going to see the Commonwealth.)

Go to Rachel and talk to her when Bobby is in the clinic to complete the quest.