Valuable information, except the information regarding why Sarah and her daughter are not eligible for premium assistance in incorrect.
Sarah and daughter are not eligible for a subsidy because her husband’s coverage is deemed “affordable” for him and the plan offers to cover the rest of the family. How much it costs to cover the rest of the family is not relevant to this situation. This is known as the “family glitch”.
If his plan did not offer to cover the rest of the family, then the household income would come into play.