In this sentence, Sy ryg die soom ..., sy is the subject, so it means she.
A quick comparison:
Afrikaans does not capitalize these pronouns unless they begin the sentence, so you work it out from the sentence structure.
In a sewing context, ryg usually means something like:
In this sentence, it is probably being used in the sewing sense: she is working the hem with a temporary or preparatory stitch before fastening it.
So it is not the everyday English verb to rig. It is a sewing word here.
Steek ... vas is a separable verb expression. In this context it means something like:
The important grammar point is that the idea belongs together:
But in a normal main clause, Afrikaans often splits separable verbs:
So steek appears earlier, and vas moves to the end.
Because vassteek is acting like a separable verb.
Afrikaans often does this with verbs made up of:
Examples:
So in your sentence:
That is why vas comes at the end of the clause.
Afrikaans verbs usually do not change form according to the subject in the present tense.
So the verb stays the same:
And likewise:
This is much simpler than English, where we say I stitch but she stitches.
Because Afrikaans, like English, can leave out the repeated subject when the same subject continues across two coordinated verbs.
So:
means:
You could think of it as short for:
But repeating sy would usually sound unnecessary here.
Yes, it is the same basic verb, and that is something learners often notice.
Steek has a wider range of meanings, including things like:
Many Afrikaans verbs cover a wider range of meanings than one exact English verb does, so you have to learn them by context.
In a sewing sentence like this, steek is not about stabbing someone; it is about stitching or fastening fabric.
The basic structure is:
So:
Subject + verb + object + and + verb + object + particle
That is a very normal Afrikaans pattern for a main clause.
Good question, because this helps show the separable verb pattern.
In a main clause:
But where the infinitive or verb cluster appears at the end, the parts often stay together:
So learners often need to recognize both:
They are the same verb idea in different sentence structures.