Good calculation. Here are my estimates on some items:
2br apartment is $1,600, not $1,200.
Food for both of the is more like $1,000.
I think that she purchased the furniture
I also think that her income from YT is between $2,000 to $4,000. Her medical bills on installments would be probably $1,000/month.
It means that unless she can increase her YT income, she has no room to maneuver, so to speak. I have a feeling that if she cannot make ends meet, she will start to resent Becky playing all day on her PS2.