If, however, she were booking tickets for Royal Ascot (in order to observe the Sport of Kings) she'd be spoilt for choice.
Roger & Sheila inform me that if you visit the race-course's on-line site, the menu in the name and address field has in the region of 30 different options, including: 'Dowager Countess', 'Right Reverend', 'Major-General' and 'His Excellency' to name(drop) but a few.
"One can imagine," says Sheila, "the fun they must have had in the Ascot ticket office working through Debrett's to find all possible titles that might be necessary."
Roger (who is, as he says - without a trace of bitterness, I am sure - "just plain Mr") adds: "I'll have to get my brother-in-law to complain that there's no designation for 'Past Master of the Company of Watermen and Lightermen'!"
With so many problems in life, it's good to know that there's one thing one doesn't have to worry about!