Famously, the two-syllable vs. three-syllable pronunciation of “medicine” was a class marker in British English - it gets some attention in Nancy Mitford’s “U and non-U” essay. The same is true of “regiment”. And I think this still holds good, at least to some extent.
The same is true in Ireland, though perhaps to a lesser extent. I speak Hiberno-English, and I pronounce both “medicine” and “regiment” with two syallables, but my impression is that most Hiberno-English speakers would have three syllables. This pronuciation comes from my father’s side of the family who, a couple of generations back, had a bit of land (i.e. more land than they could farm themselves) and a modest social standing.
Sadly, all I have inherited is the two-syllable pronunciation of “medicine”.
You’re right, but part of the problem here is that when you ask people how they say something, they tend to be more careful in pronouncing it than they might be if the word arose in their common speech - medicine is definitely three syllables for me, but the middle one is at risk when I am speaking fast.
I happen to concur with her on this particular word, but I’ve a feeling she’d also say ‘veg-e-tab-les’ as four distinct syllables, which I somehow know is correct, but never actually do, and ‘Wed-nes-day’, which I only sometimes manage.