If a parent is primarily staying home to care for a child or children (i.e. not working, or working less than full-time) will income be attributed to that parent?

Possibly, if home to care for a joint child. Definitely, if home to care for a non-joint child. The law includes a rebuttable presumption that a parent can be gainfully employed on a full-time basis. What used to be called “imputed income” is now called “potential income.” See Minn. Stat. § 518A.32, subd. 5.