objects - How to separate a possessive adjective from its noun properly?

I will explain with examples.

I sat between her and the door

I sat between her and her bag.

"her" would mean the girl herself, in the first example, and it would still mean that in the second example.

Because what only matters to me is that you didn't steal any of her and her friend's money.

So, would "her" in the third example mean "herself" instead of "her money"? If yes, then how should I fix it?

I didn't write (her money and her friend's money) to avoid redundancy.

Answer

I didn't steal any of her and her friend's money

There her is a possessive adjective. her money, the money of her friend.

I sat next to her.

There her is the objective case of subjective/nominative case she.

The object of a preposition is typically in the objective case.

... with her, to her, beside her, of her, on her, under her, over her, in her etc.