Mrs T praises Bechuanaland, sort of

Dear Seretse Khama, she writes, I and the late Mr Trellis followed your career with great interest, mainly because we had a nephew who worked for a while in what was then Bechuanaland, and who sent us postcards of the Kalahari every month. All that sand and thorn trees. It looks a very boring place, begging your pardon.
He told us what a fine ruler you were, etc, and how you didn't believe in aparthideness, whatever that was.
Thank you for telling us about Mrs Ramotswe, and please tell her that if she is ever in North Wales, she is welcome in my house for a cup of tea and a slice of bara brith any time. Is she black, by the way? Not that it matters, you understand, but I have to prepare the neighbours, they never having seen anything foreign, except for the occasional English person, who, as you know, you can't trust, even if they are white.
Yours respectively
Blodwen Trellis, Mrs, Widow, Retired.