I've recently started learning german.
Some basic grammar and the difference between "sie" and "Sie" is sometimes confusing, especially in a weird exercise like this:
"Sie und ihre Mutter und ihr Vater gehen."
How can I tell if this means 'She and her mother and her father are going.' or 'They and their mother and their father are going' ?
Without further context it's impossible.
The following translations/interpretations are possible, order from most likely to least likely:
She and her mother and her father go (Anna and Anna's mother and Anna's father)
They and her mother and her father go (Anna's friends and Anna's mother and Anna's father)
They and her mother and her father go (Anna's friends and Anna's mother and Beth's father)
They and their mother and their father go (The siblings Anna and Christine go together with their parents)
They and their mother and her father go (Anna and Christine, their mother and Beth's father)
... (I'm too lazy to list all permutations, because this gets very exhaustive and just confusing more unlikely)
Usually when refering to pronouns, you would point at the respective people or the respective people should have been introduced before. In case of ambiguity, names should be used.
Sieandsiebut asks about the translation assheorthey. Notsheandyou. As such, it does not seem to be a duplicate to your linked question.