No, but I do think an increasing share of full-time two-parent families are unmarried (and married families aren't necessarily living together), and people can get married or begin cohabitation after a child is born, so comparing rates of unwed motherhood is misleading on the magnitude (though consistent with the direction, so far) of any change in the share of children living in single-parent families.
There's no reason for an indirect proxy when the actual figure of interest is available:
Sure, the majority still are together, but the gap is widening. Quoting your link:
"During the 1960-2016 period, the percentage of children living with only their mother nearly tripled from 8 to 23 percent and the percentage of children living with only their father increased from 1 to 4 percent."
That means the percentage of families living together is declining.
Thanks for the link BTW. That data is way more relevant than the marriage statistics in this conversation.
There's no reason for an indirect proxy when the actual figure of interest is available:
https://www.census.gov/newsroom/press-releases/2016/cb16-192...