No. It is not taxable income. You would need to keep track yourself for situations like this when you need to determine support.

Some states allow a credit for low income households that is based on your overall household income.  What is included in "household income" depends on the state, but can include the working income of everyone in the house, plus any social services benefits received by people living in the home.  You have to keep track of this yourself.  Your state DSS might keep track for you on their web site, but you would have to ask them or check their web site.