Here's some tea regarding the christening that I found on Tumblr:
"I’ve met the Earl Spencer’s wife through my work in preservation/curation but also my husband’s work in non profits/charities, she’s a very warm friendly woman and takes great pride in her husband’s family and history, future and so on.
I met with her just after the christening of Archie, and we had just finished up our business for the day, when I asked politely about how the christening was as I had three godchildren myself so loved christenings, and asked why her husband wasn’t in the photo but his sisters were
basically the Earl Spencer is even worse when it comes to using Diana than William is and hates anyone trying to profit off her or use her name etc which is why he’s not pleased or happy with H&M at all and doesn’t want anything to do with them. He’s quite protective of his sister’s name and reputation and legacy & apparently he & the sisters didn’t agree with including their names on the birth announcement either and
Harry threw a fit when Earl Spencer refused to do the christening photo. Earl Spencer’s daughters are also not happy that they are continually referred as Diana’s nieces though apparently but are more low key, strong connections to SA themselves.
Apparently Harry forced the sisters to appear as otherwise he’d slander them as racist in the press.
Earl Spencer is apparently very close with the Cambridges and they visit him every so often & they go to visit Diana together."