Garden of Sins is the sixth and most recent (2022) in Laura Joh Rowland’s Sarah Bain/Victorian mystery series. I haven’t read any of this series, but have really liked the books I’ve read in her Sano Ichiro series – which don’t go on sale often enough!
Garden, however, is on sale in the US ($2.99) and UK (£2.15) right now.
Garden of Sins is now $1.99/£1.42 in the US/UK. The links in the OP are still good.
The Woman in the Veil is the fourth in this series. It’s on sale at $1.99 in the US, and is also £1.20 at Kindle UK.
Kindle US: https://www.amazon.com/dp/B07QDJNBJC
Kobo US: https://www.kobo.com/us/en/ebook/the-woman-in-the-veil
Kindle UK: https://www.amazon.co.uk/dp/B07QDJNBJC
Also, the sixth book in the series, Garden of Sins, is still £1.42 at Kindle UK, but isn’t on sale right now in the US. Info and links are in the OP.