So she is no longer a royal but still uses the title...interesting.
And Gillibrand needs to get stuffed...how dare she.
Tit for tat...just sayin.
She’s married to a royal, but she is not a royal.
When the Duke and Duchess of Sussex withdrew from royal duties they gave up using the Style of “Royal Highness” which had been granted by The Queen. Legally they can use, it but they voluntarily stopped using it, but could again if they resumed public duties.
They are still members of the Royal Family as are their children.
The title of Duke of Sussex (and subsidiary titles) can only be withdrawn by Act of Parliament and the last time it happened was World War I.
https://en.wikipedia.org/wiki/Titles_Deprivation_Act_1917