If it's the one on the right, definitely a "she" - very unlikely to be a "he"
The red gene is sex-linked, and, due to its relative size compared to the other genes that define a cat's coat colour, can only be sited on the X-chromosome.
Ergo male cats* can only either be red or non-red, as they can only ever carry one copy of the gene. For a female cat to be ginger, she needs two copies of the gene i.e. OO. But if she only has one i.e. Oo, then she will be tortoiseshell.
Looking at the facial construction, I'm hazarding a guess at some kind of dwarfism. It affects cats in the same way it affects Humans.
If you can get panacur, you can put the wormer in their food. I'd be looking at sourcing from online pet pharmacies - pet shop flea and worm products are near enough useless. I would suggest fleaing them as well, because fleas are the intermediate host for worms. Just be aware that these products are dosed by weight, so you will either have to look at kitten products or do some maths.
*Of course, if you have a male cat who has an extra X chromosome, or you have a cat who is a chimera, then you can get a tortoiseshell male. But they really are rarer than hens' teeth.
