A quick investigation of the members list reveals that there is, as yet, no Member Gordon H. Bennett on the forum yet.  This leads me to believe Member Barrett has posted this in the wrong place.

Mr Logic

Personally, I would put a 'the' before 'compulsory' in the second (that is to say, third) version.  But that's a stylistic one.  I think the first (second) is the most fetching myself.

There's an interesting shade of meaning implied by the word 'compulsory' in this context, which would be altered by the alternative 'compulsorily', weakening the effect of the key word within the sentence, quite apart from weakening the overall rhythm, too. Whilst the adverbial modification might simply suggest that the complusion in the subject's act of turning may be of her own volition, the adjectival, as written, implies a compulsion which may well be external, and thus beyond her control completely. Its very strangeness renders it the stronger, particularly as its second syllable appears to be the climax of the whole sentence.

 The two alternatives are weaker by comparison, I feel. A slavish adherence to grammatical correctness, rather than the aim of producing clear and communicative prose, is surely one of the roads to tergid, univiting writing.

(Oh, the perils of typing at speed whilst also involved in other pursuits! However, since my accidental forms of 'turgid' and 'uninviting' have already gained immortality in the "Glossary Thread", I let them stand.)

((It's a fascinating elaboration.))

Yes.  I had tea with big Jean Sibelius last night.  He elaborated fascinatingly on the grey clouds of his fourth symphony and said if I didn't like Finland he would strategically place a piano on the end of my nose whilst letting loose some mythical swan.  Yes.  Fascanating chap.  Tomorrow, it's breakfast with Bruckner again.

Meanwhile, back at the University...

Is begging the question actually a 'fallacy' though? Mathematical proofs which start with axioms and draw out their logical implications could correctly be said to be 'begging the question' (in the original sense). But we wouldn't want to say those proofs are fallacious. The fallacy, presumably, isn't to be found in the act of 'begging the question' itself but in any separate claim that one hasn't so begged it.