I’ve read a description of the conversation and it’s nowhere near as simplistic as you say. Lady Hussey, I think, was making small talk in the way she was used to doing - in her role she would meet many people, maybe just for a few minutes. The issue arose because the lady she spoke to had adopted an African name and was in the dress of an African nation - her choice, no problem on the face of it.
Lady Hussey went into her familiar small talk mode and asked her where she was from. When the lady replied naming an area of London, LH persisted and said something like “Yes, but where are you actually from originally?” There is absolutely nothing racist about this exchange - it may have seemed crass, but considering the lady was in African costume with an African name, fairly understandable.
I think only someone looking to make trouble would consider that exchange racist.
I can’t remember whether LH then also touched the lady’s hair or clothing…I may be confusing the incident with something which happened to Emma Dabiran….
If in fact she did, then that was unacceptable and presumptions, but again, not necessarily racist. I’ve had strangers touch my hair and clothing in the past for various reasons, and I’m white British. Not welcome, but not racist in either case.
I remember this because I took an interest at the time in this incident and read a lot about it.