expressions - I can't understand this sentence. It's from a video game Baldur's Gate

I don't speak English well. Please understand my bad grammar.
I'm not a native English speaker.

Recently I am playing a video game Baldur's Gate in English.

And I found this from the game.

Dreppin: "Nice day, ain't it? Too bad Nessa here ain't enjoyin' it though, her bein' sick 'n all. I need to get her one of them potions of antidote off Hull."

I understood almost everything what the charater said to me.

But still I don't know why the character used "her being sick and all."

Nessa = female cow

She's sick now. I understand.

But why her being sick? not she is sick or she has been sick or she is being sick.

Why there is no verb in the sentence?
Also how can the character starts the sentence with her, not she?

I mean, we use her usually her ring, her bag as a pronoun. like this.
But the character said "her being sick and all."

< it doesn't seem to make sense. Because it's a video game, so just because of that is it ok?

And what does meaning of "and all" ?

her being sick and all. means the female cow is sick now and what?

I don't get what and all means in this sentence.

So please explain the meaning of these things

• meaning of and all


• why her being sick and all / why there is no verb in the sentence


• why her being sick / why the sentence starts with her, not she

Those are my questions. Please help me.