its VERY rare to get a tortie male, so shes likley a girl, though ive never seen an orange based tortie usually black with orange patches not the other way round) so shes going to be a very cool looking little kitty
given the size difference id say you have 2 differetn daddies for this litter too, the orange kitten looks a good 3-5 days older than the little ones. this is fairly normal
im sorry you lost #1, its a hard lesson for the girls, but it is a good one, life is fragile and you did wll you could to help that little one thrive, sometimes no matter what we do we loose one...you tried, and that in itself is more than some folks in this world can say.
personally im of the 'pick the babies up daily" mindset when it comes to animals, as long as momma isnt stressed, let your girls go in there 1 at a time and touch/hold each kitten for a few seconds right now...if momma seems stressed or upset, then give her a couple of weeks, but even while still blind and deaf, the more short pleasent interaction they have with humans the easier it is to get well rounded kittens...
ive raised many litters, (have one right now) and each morning and then again before bed, from the day of birth, assuming mommy cat is not showing signs of stress, i spend just a few seconds, i pick each one up, give it a gentle pet touch its toes, weigh it and then put it back...
it SOUNDS like your momma kitty is very mellow and wouldnt mind either.
weighing them, especially with orange kitty so much bigger than her sibling, is a good idea to make sure shes nor monopolizing all the milk.
also spend a few mins each day a couple of times a day giving momma a check over, with only 2 kittens you want to make sure all the niples are getting use so she doesnt develop any mastitis issues, ive found momma cats seem to like their tummies rubbed so i make it a big part of some quality time, gently feel each mamary gland, give if a gentle squeeze, it should be warm and if full should feel full and but still have a little give...if it feals HOT, or like a big hard lump there could be an infection forming.
its rare, but does happen with small litters. ive found the best way to prevent it is to make sure the kittens are feeding off different nipples a couple of times a day.
oh and another RULE of mine is a new picture every day
its easier to see them grow that way.
i love raising kittens, i frequently end up being found by stray pregnant kitties, so ive been through it a few times lol, its heart breaking AND joyus all at the same time.
side note, let me know where to send the self adressed box so you can pack up that little orange kitten once shes old enough and send her my way