Child Support Question

If the male non-custodial parent and their new partner are living together, not married, can his partner file a child support order for their new child against him even if they are still living together?

If she does not have this right, and she does anyway saying they are seperated, would the burden of proof to disprove they are not seperated, be the child support office or the custodial parent contesting it?

A child support claim can be filed while two parents are living together, however an order of support will not be issued until the parties actually separate.