<human>: Can you condense the text into a few key points?

Hey Reddit, I'm still really new here but I really need advice.

 Okay so, my mom has been going in and out of the country to see her father who had terminal cancer. He died in February, and last week she left again for I don't know what. 

 She left my sister (23 - unemployed), my step-dad, and me with no groceries, and no money. Every time she's left out of the country before she always asks for a ton of money, but this time she was only supposed to be gone for ten days. 
It's been 5 days and we have no money or food, she got my step-dad's whole check and asked for 250 dollars two days later. Yesterday my step-dad sent her another 300, he was asking my oldest sister for money for lunch.  

 I really hate seeing him so stressed out, I try to cook for him when he comes for lunch but all we really have is eggs and chorizo, we barely had enough money for milk.  I can see he's getting upset and she won't tell us what she's spending all this money on, I mean like one dollar here is like 22 there. She says she's using it to make her father's grave look nice, but I mean she bought a really nice coffin for 70 american dollars. 
 
 I don't know what to do, my sister (23) is still looking for jobs and I'm 15 so I can't get a job. My mom called yesterday and extended her stay by a week, I don't think we can keep going on literally nothing. I'm really worried because my step-dad is really overworking himself and there's not that much I can do for him.  

 What should I do?
<bot>: My mom has left us with no food or money and is continuing to take my step-dad's checks, I'm too young to get a job and my sister is on the hunt