Pronoun help

[ShobhitK282]

I have a quick question on one of the stimulus I read in OG.
I have created an example pretty similar to it just to clarify a doubt. This doesn't relate to solving this particular problem.

Part One:

S: The plot of Kyunki centers on the rivalry that develops between Olive, an active feminist, and Basil, her charming cousin.

I'm not sure how can her in the sentence refer to Olive and not Basil? Although logically, her seems to refer to Olive but I'm not sure how is this usage justified?

Part Two:

The plot of Kyunki centers on the rivalry that develops between Olive, an active feminist, and Basil, her charming cousin, when they find themselves fighting for the same trophy

Clause after when explains the plot. I wanted to understand the role of "when...." in this sentence. Isn't when used to refer to time?

[RonPurewal]

I'm not sure how can her in the sentence refer to Olive and not Basil? Although logically, her seems to refer to Olive but I'm not sure how is this usage justified?

1/
"Basil" is a man's name.

2/
Even if the sentence described two women"”"”let's say, "Olive, an active feminist, and Sophie, her best friend""”"”it's impossible for "her" to refer to Sophie. (That would just be Sophie's best friend.)

[RonPurewal]

Clause after when explains the plot. I wanted to understand the role of "when...." in this sentence. Isn't when used to refer to time?

That's exactly what it does.

When does the rivalry develop? It develops when they find themselves fighting for the same thing.