Hey there,
Stixjeat
It sounds like you're having some trouble with a quest in the game. Specifically, it seems that there's an issue with the grandmother's behavior during the quest. According to your post, she vanished after you spoke to her and didn't walk over to the mother's tent as intended. This resulted in the dialogue not triggering and the quest not being completed.
If I understand correctly, you tried walking back to the mother's tent to see if the quest would complete, but that didn't work. When you returned to the grandmother's tent, she was still missing. However, the quest didn't indicate that it had failed.
It's possible that this is a bug in the game. If that's the case, you might want to try restarting the quest or reloading a previous save to see if that resolves the issue. Alternatively, you could try contacting the game's support team to report the bug and see if they can help you find a solution.
I hope that helps, and good luck with your quest!