yes they are
Just that, female conjoined twins. In some languages all nouns have gender, so in French, Les Jumelles Siamesienne, the enne suffix would mean female. By the way, conjoined twins, being also identical twins, are always the same gender.
No but Halloween was featured on their first special: Twins, Twins and Sextuplets.
yes but only if you marry a special type of alian
She was one of twins, her twin sister is Artemis.
There are 12 regular episodes and one special.
A twin is still a single, one has twins. So, "twins' parents."
The twins only feature in cutscenes so far.
Yes a C-section is only needed in special circumstances
They could be or couldn't be. It all depends on the special genetics.
No. All identical twins are the same sex. Judith and Hamnet were opposite sexes, and so were fraternal twins.
Yes, horses can have twins, but it is not very common.