Should have been
Millie,
Molly and
Mandy ... if the parents absolutely insisted on the same initials, they could have introduced a bit more variety:
Melanie,
Marianne and
Maeve springs to mind. And, only one trip with a mn - and it's also an M name. I'm guessing their ln is huge and hyphenated: Montague-Middleton-Marx, perhaps? Fine, as long as nobody ever gets sinusitis.
Seriously, social media give exhibitionists too many opportunities to show off. It's fine if it's just them, but this lot, if they are real, haven't done their new daughters any favours.