I realize this is a subject that is asked much too frequently, but I see a lot of possibilities for side gigs.
However, I believe that this is a reasonable request—not outrageous like $10,000 a month.
I’ve tried a few different things, but I’d really like to talk to more seasoned side hustlers.
My monthly income from photographing for book covers is about £2k. 
For the past 17 months, I have been walking and sitting dogs, and I have made an average of $900 every month. It was something I kind of fell into after getting my own dog two years ago. It’s ideal for me as I can exercise my dog for money and it gets me outside, moving, and healthy. While some months are more difficult than others, most jobs are ultimately worthwhile.