Could Brulee and Montd'or be twins as well? I'm only basing it on the noses, and that grouping up the Kata3 and Opera5 Montd'or falls down to the 13th pregnancy with a boy, and the lack of information on the girls side specially of the single digit ladies make everything kind of fuzzy. It's anoying to have the full list of brothers from 1 to 10, and just daugthers 1 and 8.
We only have few spaces with fully explored order of births:
Compote and Perospero are the eldest, but between them there isn't an order yet and they could be twins.
Then thanks to Flampe we have Katakuri, Daifuku and Oven as the 2th, 3rd and 4th sons, as he he has 38 little sisters, out of 39 Charlote sisters, so they are deffinitelly the 3rd to 5th kids.
Then from here we can't pinpoint anything else relative to boys and girls until Mascarpone and Joscarpone, being the 34th son and 29th daugther, so we have that the boys side's number has been bosted by just 5 extra.
Then Flampe has 35 (right?) older sisters, and 41 older brothers, leaving just 3 girls and 5 boys younger than her, at the very least Anana and Anglais are surelly younger ("can I kill them mommy" girl and "biker" boy)
Big Mom produced her family over 42 years, with 43 husbands, probably one pregnancy per husband. Katakuri being 48 (per SBS answer), and Big Mom herself being 68, means that she had Katakuri and co. at 20 years old, keeping it legal, let's say that she had either Peros or Compote at 18 at the earliest, 19 and twins at the latest to start, then she stopped having kids at: 60. Around 8 years ago, so the youngest Charlottes are that age.
If Flampe is 15, and has 8 younger siblings, then.. at most only one of those pregnancies was multiple, and it was only two babies. Well, considering this is ages, and Big Mom could had shorter pregnancies, and could get knocked up quickly to squeeze the extra pregnancy to fill the last few slots.
–- Update From New Post Merge ---
Chiffon and Lola are aparently 26 years old.
I was under the impression that the 10-pregnancy of Big Mom 18 years ago yielded 5 boys and 5 girls, if so, that would limit Pudding's age to a maximum of 18, as while we have many holes in the girls side, they are conveniently over 5 people, from Lola the 23th, to Joscarpone the 29th to Pudding the 35th.
On the boy's side after Mascarpone the 34th we have no more numbers, and before him the 26th son introduced a few chapters ago.
So the Decaplets can't be all girls, and if they are all boys they can't be older than Mascarpone, but then, they can't be younger than him, because we know that Flampe has 5 younger brothers, if we put the decaplets after Mascarpone, that leaves just 2 sons left.
So the Decaplets have to be both boys and girls, with the absolute maximum of 7 boys (between Mascarpone and the 26th, or Mascarpone and the unknown 42th). And an absolute maximum of 5 girls.
Of course that is asuming the scarpone twins nor Pudding aren't part of the decaplets, that would mess up my calculations. Also I have the feeling that we have enough info to put the scarpones over 18 years old but I'm still digging.
--- Update From New Post Merge ---
If the word is Twin then they are just them, but I'm not familiar with the japanese words for siblings of the same pregnancy, nor the actual words in any language.