Second guess: Liz is female author's father's second wife. Ailing, but finishing college as an older student.
Absolutely nothing about the content, lettering, or drawing suggests a male author to me. FWIW!
Maybe Liz is her younger half-sister from a temporarily estranged parent. :)
I realize I'm plumbing the depths of statistical likelihood to support my intuition of a female author.
Two other things occur to me. In the 1980s, there was a wider variety of what was considered "ordinary" in the expression of stereotypical male traits within gendered males. It was much less expected for any in the gamut to follow a non-stereotypical path, of course, and for better or worse.
But more directly relevant, the author is "anonymous" but certainly not "unknown", so it probably makes sense to assume that the auction house / article writer got it right in the first place!
So the author was introduced to Liz on 1978-01-21, and married someone on 1979-05-05. It's possible that's Liz, but that's fairly quick, even for the 70s.