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.