In the 1930s Egypt had become a popular resort and visit and explore. Agatha Christie’s book Death on the Nile helped promote it in England and Europe to people who found European winters trying.

Fashionable doctors recommended a visit there to their well-to-do patients.
Melba found plenty of old friends there, mostly in a frail state of health. She was not well either but did not miss the opportunity to do some sight-seeing. (1)

Besides sight seeing Melba, ever the opportunist and business promoter was quick to write to son George and Cave Hill.

Kashabanarti, Assouan
George dear,
Thank you for your letter, so interesting to me. I am glad you are playing polo because I know how much you love it. Egypt is glorious but the house party is dull …sol sneak out & cadge a meal from Bemberg, who is staying at the hotel. He is always merry & bright but, oh! so frail & changed. I don’t think he will be here much longer, which is too sad. He sends love, too.
I was motored by Sir John Norton Griffith to see the wonderful work on the Nile which is simply stupendous. The water floods bigger & faster than Niagara Falls now. The water will rise 35feet and could well bring in £12,000,000 more a year to Egypt. If only we could do something like that in Australia. The position there is very serious. I don’t know what will become of us all. Please have some olive trees planted. I have written to Olivieri about it — it would become a paying proposition. I am feeling a little better, I am hoping to see you in October if I am still alive.
My love to all, Mother.
Do tell Pamela she ought to say I received your letter, not I got, so ugly.

In February 1930 she wrote from Luxor:

Luxor Winter Palace,
Luxor,
Dear George,
I have ’written to Mr Watson, asking him to send some Limil to the Assouan Dam, as they are having great trouble ‘with the cement which cracks so much that they don’t know what to do. This is a colossal work, the contract is worth L4,000,000 so it may mean a big order. Will you please see him at once. I have given all details — the contractors name is Sir John Norton Griffith, such a nice man & his wife & daughter are charming I think the resident engineers name is MacDonald but I am not sure. I hope to get to Paris in about three weeks & I shall be glad.
Bless you, Mother
This may mean a big order & a wonderful advertisement, the work will take 3 years. (2)

References

(1) P. Vestey, Melba A Family Memoir, Pamela Vestey, Coldstream, 2000 pg 236.
(2) P. Vestey, Melba A Family Memoir, Pamela Vestey, Coldstream, 2000 pgs 237-238.