Hey there!
First, let's take all of the expenses and change the ones that aren't monthly into monthly.
Groceries: $800/month
Car insurance: $87.5/month
Gasoline: $100/month
Now, let's add together all of our expenses
1090+800+125+87.5+100+200+50=2452.5
Now, we subtract that from her salary.
2300-2452.5=-152.5
Therefore, Rebecca's net monthly cash flow is -$152.5. She should spend a bit less on groceries, not do so much miscellaneous, find a place that charges less rent, drive less, etc. so she isn't spending more than she earns.
I hope that this helps! Have a wonderful day!