What does "respective lots" mean in this context?
This is from the book, After You. Here, narrator, I, is talking about her sister, who's a single mother with a noisy, prankster kid.

I'd felt a sudden sympathy (towards her). She was right: I had been handed, against the odds, all the advantages - a home of my own, a future free of any responsibilities - and the only thing stopping me embracing them was myself. The fact that she wasn't eaten up with bitterness over **our respective lots** was pretty impressive. I hugged before I left. She was a little shocked, then momentarily suspicious (...) then finally hugged me back.

I'm not sure about the meaning of the part marked in stars here. Since you wouldn't know the whole story, I'm not asking you what exactly "respective lots" would refer to, but rather what they mean in a vocabulary sense?
(Especially I don't understand why it's "our..."? From the context i guess she should've said "I was impressed that my sister wasn't being bitter over *my* life" or sth.)

Thanks in advance.

Question

What does "respective lots" mean in this context?
This is from the book, After You. Here, narrator, I, is talking about her sister, who's a single mother with a noisy, prankster kid.

I'd felt a sudden sympathy (towards her). She was right: I had been handed, against the odds, all the advantages - a home of my own, a future free of any responsibilities - and the only thing stopping me embracing them was myself. The fact that she wasn't eaten up with bitterness over **our respective lots** was pretty impressive. I hugged before I left. She was a little shocked, then momentarily suspicious (...) then finally hugged me back.

I'm not sure about the meaning of the part marked in stars here. Since you wouldn't know the whole story, I'm not asking you what exactly "respective lots" would refer to, but rather what they mean in a vocabulary sense?
(Especially I don't understand why it's "our..."? From the context i guess she should've said "I was impressed that my sister wasn't being bitter over *my* life" or sth.)

Thanks in advance.

Answer

One’s “lot in life” is one’s life situation. The expression suggests that the situation is largely a result of chance, fate, or destiny. The word “lot” is also used in the expression “to draw lots” (although it's probably more common to draw straws these days), and is the root of the words "lotto" and “lottery”.

Answer

“Lot” here is short for “lot in life.”  It is related to the word “lottery.”  The idea is that, through luck (like in a lottery) some people get good things in life (money, health, an easy life, etc.) and some people don’t.   “Our respective lots” means “my lot in life compared to your lot in life.”   So, your understanding is basically correct:  The sister wasn’t bitter about the fact that his life was a lot easier than hers.