Calculating CS and Support for In-Law

[blinkandimgone]

This is a two part question on behalf of a new poster that is unable to post just yet:

1 - Background:
50-50 arrangement, offset child support being calculated. One spouse (Spouse A) has recently started a new job a few months ago after quitting previous job last year.

Question:What amount should be used as spouse A's income to calculate CS for the remainder of this year?

2 - Background:
Spouse A's parent has lived with the couple for 5+ years and has provided childcare for the children, even while the Spouse A was at home. Spouse A has moved out and their parent has moved out with them, Childcare is still being provided for the children at both homes from their grandparent. Spouse A is now saying support will need to be paid to their parent as well because they also moved out. Spouse B has no problem paying the grandparent for childcare services at their home, or finding another caregiver in their home that does not complicate family issues.

Question: Is there any way Spouse B could somehow end up on the hook to support Spouse A's parent in this scenario?

 

[HammerDad]

Situation A - It would be easiest to simply use the new income as C/S going forward. But I think the common reply will be to go off line 150 for 2015 tax return, and adjust next year off the ex's 2016 line 150.

Situation B - Spouse B will NEVER be obligated to pay any sort of support to Spouse A's parent. If Spouse A's parent provides care-giving services to the common child, then they are entitled to be compensated for that. But outside of that, there is no obligation to support another person's parent. If Spouse A is supporting their parent, they get to claim the tax credit. There is no chance Spouse B would be able to claim the tax credit, so why are they contributing?