Since $133 is equal to 7% of her earnings, then 1% is equal to $133/7 = $<<133/7=19>>19.
The total monthly earning of Zilla is represented by 100%, so $19 x 100 = $<<19*100=1900>>1900 is her monthly earnings.
So, $1900/2 = $<<1900/2=950>>950 is spent on her other monthly expenses.
The total amount spent on the rent and other monthly expenses is $133 + $950 = $<<133+950=1083>>1083.
Hence, she saves $1900 - $1083 = $<<1900-1083=817>>817 per month.
#### 817