No values for fstatmom (and others) for sample child

I’m downloading data via the ipums interface and find that the variables which are supposed to pull a variable from a sample adult (i.e.; food security) from the sample adult and put it as a new variable into the sample child have no observations in my downloaded data. I’ve tried this for several variables with the same results. The other downloaded data is populated with cases. Am I doning something wrong?

The ‘attach characteristics’ feature is not available for NHIS samples after 2018 because of a survey redesign (see this IPUMS note and this NCHS page). In samples from 2018 and earlier, households are randomly sampled to participate in the NHIS. Questions are asked of or about each household member. In samples from 2019 onward, only basic demographic information on household members is collected with one sample adult and one sample child in each sampled household randomly selected to complete the rest of the survey. The sample adult and child do not necessarily need to be part of the same family. As a result, the family interrelationship variables that the attach characteristics feature is based on, including RELATE, are no longer possible for IPUMS to create. For the 2019-forward data, NCHS does provide a variable identifying cases where the sample child is the child of the sample adult (available in the IPUMS variable ISPARENTSC).