APA style - citing nobility

I want to cite a written work by a European (specifically, English) nobelwoman, more specifically, a countess.

However, in order to make my question a bit general and to provide a comparison case, let me start with another example, Andrew Lloyd Webber who was made a baron in 1997. According to Wikipedia, he is properly styled as The Lord Lloyd-Webber.

However, I assume that is irrelevant when citing his work on the musical The School of Rock, so I would write in running text Lloyd Webber (2015) (without the hyphen), and in the bibliography, write

Lloyd Webber, A (2015) The School of Rock (original score). London: Rodgers & Hammerstein.

But perhaps I'm wrong (see below).

The case I'm currently concerned with seems at least a little more complicated. I want to cite Augusta Ada King-Noel, Countess of Lovelace. She is usually known as Ada Lovelace. In the original work I want to cite, she is only credited by initials, and those initials are A.A.L, or variously (probably a typesetter's error) A.L.L. In any event, it seems clear that she is going by "Lovelace" in that work rather than by "King-Noel".

Therefor I assume that I should cite her as Lovelace (1842) in running text and as

Lovelace AA (1842) Translator’s notes to M. Menabrea’s memoir on Babbage’s Analytical Engine. In: Taylor R (ed) Scientific Memoirs, vol 3, London: Richard and John E. Taylor, pp 691-731.

(dropping the King-Noel) in the bibliography.

However, since this differs from my intuition about the example above, I'd appreciate any advice that can resolve the issue.

The examples are substantively different as one is himself a Life Baron (the lowest level of the peerage, and not hereditary) and the other is the wife of a (hereditary) Earl.

Although earls have a surname, King-Noel in this case, they don't use it and instead identify themselves exclusively by their title. Ada's husband, after his creation as 1st Earl of Lovelace in 1838, would have signed himself as William Lovelace (or, probably, just the single word Lovelace). Once he adopted the name, Ada would probably have signed herself as Ada Lovelace.

It's slightly more complicated because, prior to that, he was a hereditary baron, the 8th Baron King and his surname was King (as was hers; she was Lady King). Ada was descended from the extinct first creation of the Barony of Lovelace, but it's not clear why that title was chosen for her husband. He only adopted the additional surname of Noel in 1860 — after Ada died in 1852.

Use the surname Lovelace for Ada. It's not wrong, and it is what she was known as when translating Menabrea's article, rather than King or King-Noel — and this last probably is wrong, because it's not a name she herself would ever have used.