It is not craven defense to note that the prime-minister is a crown appointment and many functions of government are performed by royal prerogative.

Мой вариант: Не является проявлением малодушия отметить/ малодушным аргументом/защитой отметить, что премьер-министр утверждается/назначается монархом, и многие правительственные функции входят в королевскую прерогативу/выполняются с разрешения монарха.

И еще родин пассаж из этого же абзаца: It is surely to avert that outcome that she has spoken now. Мой вариант: И это, безусловно, должно предотвратить развитие событий по сценарию, который она озвучила.

Буду благодарна за помощь!

@It is only a matter of time before the Queen finds her position dangerously politicised. It is surely to avert that outcome that she has spoken now.@
I.e. The Queen HAS SPOKEN (произнесла речь в @the Sandringham Women’s Institute@ --это же там выше в статье написано! т.е. никаких "сценириев/итогов" она не "озвучивала"))
precisely because she does not want to find her position 'dangerously politicized'.
i.e. the 'outcome' in question is a 'dangerously politicized position'
Так понятнее будет? ;-)

Ну Себастиану простительно (че с него вообще взять), но Вы ведь Аскер статью переводите -- следовательно прочесть ее должны были!

I think 'surely' is being used here in the sense of 'it must be true that ........ – mustn't it?' rather than 'definitely'/'without any doubt'. In other words, I think he's speculating but saying that he's fairly sure that what he's saying is true – as in Definition 1 here rather than Definition 2: http://www.collinsdictionary.com/dictionary/english/surely

'surely?' can also be put after statements for the same reason – to say that you'd be very surprised if the statement weren't true, as in:
* 'He's now 80 years old? He must have retired, surely?'
* 'She's a billionaire but says she can't afford a bicycle? She's joking, surely?'
* 'As he's French, he must know that the capital of France is Paris, surely?'

So I think the author's speculating and effectively saying: 'The reason she's spoken now must be [in order] to avert that outcome'.

And I take it you don't see any issues with the rest of that sentence?..)
Trust me, there's a host of those and the 'surely' bit is the last one we should be focusing on!
Because as it stands, the whole sentence just don't make much sense. Either the Asker didn't quite understand the source, or he/she never even bothered to read the whole piece) Hence my detailed and laborious explanation at 18.04.2019 17:56 btw, which I suspect has fallen on deaf ears.

///is the last one we should be focusing on!
Because as it stands, the whole sentence just don't make much sense.//

Just because you didn't get it?

Аскерша у нас she, т.к. написала в конце "буду благодарна", так что кто тут never even bothered to read the whole piece... Не обижайте девушку...
В общем, не плюй в колодец, а то оттуда вылезет здоровенный жлобина и наплюёт тебе в душу...

I agree. The key word here is "NOW". Author is speculating that she spoke about this issue now (not a month ago, not last year) because now she feels that the situation put her in a dangerous position.