Problem with "A Return to Your Roots" quest?

It seems if her sister is killed, the resulting consequence would be this. It’s possible the vampire attack caused this. There unfortunately seems to be no way around this.

I figured out how to fix this bug!! It takes forever, but I had to figure it out cus of how long it took to get all of that nirnroot. Basically, the bug is caused when Avrusa's sister dies. If vampires attacked and her sister died when you discovered the farm, unfortunately you're screwed (unless you can reload that save and stop it). But if she just keeps getting killed by the dragon, what you have to do is reload your last Blackreach save (you'll probably have to find some nirnroot again but if you don't this quest will never work). Collect the nirnroot, and use the lift that the quest marker shows to go back to Skyrim. Then, fast travel to Sarethi Farm. As soon as you get there, save the game. After you've done this the dragon should be gone, and can't kill Avrusa's sister. If this doesn't work, reload your last Blackreach save again (make sure to delete the Sarethi Farm saves you just used). Gather the nirnroot and leave through the lift. Change your Shout to Bend Will (you have to have completed to Solstheim questline first). Then, fast travel to Sarethi farm. Save again. After you've saved, the dragon should land near the tower or circle around the farm before landing. You need to use your Bend Will shout on the dragon before it can attack, because the first NPC it kills is Avrusa's sister. When the dragon lands, hop on, and immediately use the right/left arrows on the D-pad (or the PC equivalent) to change the dragon's target from Avrusa's sistse to another NPC (there should be a fox or a bear nearby you can change it to). If you don't do this, the dragon will land and kill her with you on it. After you've switched the target, land the dragon. As soon as you get off, go to Sarethi's door and wait for about 17 hours (make sure to do this quickly, because the dragon isn't yours forever). After you've waited, you may need to wait some more before you can go into the house without trespassing, but the dragon should be gone. It may reappear on your enemy marker briefly but will go away. Then, you can talk to Avrusa. I know this will suck because if you've autosaved a lot you may have to go back really far to fix it, but this is the only way I've been able to figure it out. If all else fails, try fast traveling to the farm, saving, and then try to talk to Avrusa before the dragon lands and kills her sister. She is available to talk to up until the moment her sister dies, and she won't enter combat with the dragon for a while after you get there. You might be able to complete this quest while the dragon is attacking. It seems like too much work, but I hate having broken quests I can never complete in my quest log, and I can't use commands because I play on ps4. I don't even think there's any commands to fix this quest right now.

2 years late but this happened to me only bc her sister was dead. If her sister dies she will stay home and not leave. Reload earlier save