Point of divergence:
After the death of Adelaide Dubus,
Edward does not encounter his long-time mistress
madame de Saint-Laurent. He still gets posted to Canada and carries on more-or-less as per OTL there and might have a string of mistresses, but not any one he forms any long-term bond with.
Due to small butterflies during his stay in Canada, his next assignment is somewhere in India, possibly to oversee a Royal Marine force assigned to cooperate with the East India company's private army in some endeavour.
There, he encounters a princess of one of the princely states. He is intrigued by her and eventually falls in love. She might be somewhat desperate that the East India company is going to take over her father's lands and thus willing to convert to Anglicanism for the sake of her family and might come to love him in return.
While a non-European wife would be shocking to British society at the time, the fact that she is royalty would outweigh that, I believe (the much more technologically primitive Zulu kings were treated quite well after being ousted, after all. If anything, treating eastern royalty as equals would be more likely in earlier periods, methinks). The indian states at the time were tributary to western powers but nominally independent and quite a lot richer and more prestigious than the many one-barony-duchies in Germany.
The British empire might be able to leverage Indian manpower and productivity a lot better in this timeline and end up as even more of a global superpower than OTL. If an when the empire starts to dissolve, it could become a bipolar commonwealth, possibly with separate branches of the royal family in India and Great Britain. India would still have a lot more room for improvement than the UK and might, if sufficiently unified and industrialized, well be the number 1 great power by the mid-20th century.