The second entry into my Famous Astronomoms series feels a bit like a cheat, since she's not very famous, and also arguably not really an astronomer. But I check - she was definitely a mom, and I think her story is interesting so I wanted to include it.
You will be forgiven for not knowing who Venetia Phair is, especially as her only contribution to astronomy was made almost 80 years ago under her maiden name of Venetia Burney. Venetia Burney, in March 1930, was an 11 year old Oxford school girl who was the first person to suggest the name "Pluto" for the recently discovered planet. She benefited from making this suggestion to her grandfather, who happened to know an Oxford Professor of Astronomy (Herbert Hall Turner). I'm not surprised that Venetia's grandfather thought her idea brilliant enough to put it in a quick note to Turner which he dropped at his house on the way to the library (my little one's grandfather has already suggested she's a genius), but it is perhaps surprising that Turner also thought the idea good enough to merit telegramming it to the Lowell Observatory in Arizona, and that the staff there (including Clyde Tombaugh - the discoverer of the planet) liked it enough to adopt it.
This picture shows Venetia Burney age 11 around the time she named Pluto.
Venetia got widespread fame at the time for her suggestion, and a prize of £5 from her grandfather (a lot of money in 1930). Even before the recent fuss about the demotion of Pluto from a major planet there was some renewed interest in Mrs. Phair's story, with some BBC press. She also has an asteroid named after her (6235 Burney) and an instrument on board the New Horizons spacecraft (currently enroute to Pluto).
In 2006 the IAU voted to demote Pluto to a dwarf planet (rather than risk having to make perhaps dozens of outer solar system objects planets). Venetia Phair was quoted on this of saying "At my age, I've been largely indifferent to [the debate]; though I suppose I would prefer it to remain a planet", and also commented on the slight irony that interest in Pluto seems to have gotten larger after it was demoted.
Venetia Phair did not become a professional astronomer, but she did go on to work in a STEM field - studying Mathematics at Cambridge University. For a while she worked as a chartered accountant, and then as a teacher of economics and mathematics at a girls school (first in London, later in Sussex). It appears that she continued to work after her marriage in 1947, switching to teaching only in 1950. This would have been relatively unusual in the UK at the time. She only retired as a teacher in the 1980s, which is consistent with her working until past the UK state retirement age of 60 (for women). It is not commented at which point during this her son was born, but clearly she was a working mother for at least part of the time.
Venetia Phair passed away on April 30th this year, age 90. There is a more extensive obituary of her in the Daily Telegraph Science Obituaries. She is survived by her son.