I guess it depends on many factors:
1) whether you have a helper at home
2) whether your full time job is demanding and requires after working hours attention
3) whether your kids are independent enough and does not demand too much attention
For me, my full-time job is already very taxing and demands my after working hours commitment at times. I also do not have any domestic helper or parents/parents-in-law to help out in my home. So I guess earning extra income is almost impossible at this stage. Perhaps may consider this if my fulltime job is less strenous and when my child is older... Now I'd rather focus on spending more quality time with my baby boy and hubby.