McNeill attended public school in Birkenhead and studied classics at the University of St Andrews, completing a MA degree in 1929.

McNeill became the minister of a village church in Rostrevor, County Down, Northern Ireland[5] while Janet joined the Belfast Telegraph as a secretary.

[5] In 1933 she married Robert Alexander, the chief engineer in the Belfast city surveyor's department,[5][1] and the couple settled in Lisburn, where they raised their four children.

Her popular children's character, Specs McCann, who debuted in a 1955 book and made several reappearances, also inspired a newspaper cartoon strip by Rowel Friers, a Belfast artist and friend of McNeill's.

[16] She depicted the "dreary, Ulster religiosity"[9] of ministers and laymen alike, and the class conventions and sexual repression of middle-aged, upper-middle-class women.

The theme of suppressing self-identity and goals, both by wives in deference to their husbands and parents on behalf of their children, pervades her adult novels.

[17] Citing her novels Talk to Me (1965) and The Small Widow (1967), Foster writes, No other Irish writer has so clearly and consistently revealed the stark waste and despair beneath the cramped existence of these women, an existence unmitigated by illusions and made the more bitter by the women's determination to suppress any public and, if possible, private recognition of this waste.