IIRC (haven't actually read it, but Vinay Lal discussed it in his youtube lecture series on the British Raj), didn't she falsely accuse him of rape? This book (along with A Passage to India, which also deals with a English woman falsely accusing an Indian man of rape) was a counter to the "dark Indian rapist" stereotype that had been spread by the British:

It was a way of preventing miscegenation. They had laws banning Indian judges sitting in cases involving white women, and produced atrocity literature about "dark Indian rapists" attacking white women.

This propaganda started during the first Sepoy mutiny, where rumours were spread that the rebels were raping British women. There was never really any evidence provided, but the British cunningly used this hysteria to both justify colonialism (we're saving these brown women from brown men!) and to prevent White women from falling for Indian men, which was a fear at the time as such relationships would undermine their notions of racial superiority. Of course, this tactic has been used countless times on many different native populations by Western Imperialists, as members of this sub well know.

I find it pretty bizarre how few people bring this stuff up with regards to the recent sensational coverage of Indian rapes (and yes, when a gang rape hundreds of miles away is more likely to make news in a western city than a gang rape IN THAT VERY CITY then it is DEFINITELY fucking sensationalist, NO MATTER WHAT the comparative rape figures are). The comparative rape figures are telling though. India, like the rest of Asia, has extremely an EXTREMELY LOW rape rate compared to the West. Now, I know, I know, that must be due to underreporting, right? Well even adjusting for the UN's (Western biased) estimated rates of underreporting, India's rate is still far far far lower than nearly all western countries. There's also insanely high false accusation rates in many Indian cities, which isn't exactly consistent with the idea that reporting rape is so much more stigmatized in India than other countries.