SOLVED. Mystery series: Redheaded TV journalist in the east village is amateur sleuth. Spoilers ahead.

[Emily]

This mystery series had pulp-inspired covers. I read them in the 1990s and they featured a redheaded woman who investigated mysteries and lived in an East Village walkup, and I believe her job was a tv journalist. I remember she planted poison ivy in her window boxes as revenge against possible burglars, and (minor spoiler) at one point an antagonistic police inspector touched them. Also (bigger spoiler) in a late book in the series it was revealed that she had a doppleganger living nearby. I believe the author was a woman.

[Emily]

Solved! A friend reminded me elsewhere: it’s the Robin Hudson series by Sparkle Hayter.

[Ingo]

For the click:
What's a Girl Gotta Do?
(First book)

Goodreads Robin Hudson Series page