If my main and only sim in the household, who im going through the story with, is infected; can I still play through the whole story without needing the help of a another sim to fix her and/or also so...
If my sim loses the fight with the mother, she will actually die. I thought that it would kind of be like when you spar with a vampire and then you just get defeated and lose but you're still alive. I guess I'll have to prepare some ambrosia for later since a lot of people seem to have difficutlies defeating the mother. Also one person befriended it? Hoe do you do that? Do you have an option to fight it and/or talk to it? Im still at the early stages/chapters of it, so I dont really know anything about what happens at the final boss fight.
If your sim tries to fight alone, they'll get a dazed moodlet with a notification that it's best to find other sims to fight with her. If your sim tries to fight her again when the dazed moodlet has not expired (2 hours), the mother plant will eat them. Grim Reaper won't come. The urn appears in front of the platform after some time. However, from let's plays, I've seen that sims doesn't get that dazed moodlet when fighting with a team. So don't worry about that.