Jenny,
Not sure where you are located, but for Ontario:
Spousal support is pretty much no fault in Ontario as long as you have NEED and he would have MEANS. There may not be sufficient income left after deducting payable child support.
The courts would take into consideration the amount of child support that he would pay. This is generally calculated from tables which can be found here.
http://www.e-laws.gov.on.ca/DBLaws/R...h/970391_e.htm
Generally, the last 3 years income amount from line 150 of the payer's income is used. This amount is cross referenced against the tables to determine the monthly periodic amount.