My kittens are so attached to each other!

I've got 2 kittens and they are usually so attached to each other! They hate to be away from each other for more than a second, even if they are just in different rooms. Tilly will WAIL if she's away from Archie but never goes and looks for him, but he'll meow for her then go and find her. She is such a noisy little miss, and he's silent compared.
My kittens are from the same person and they're half siblings. He's a week older than she is but i think they've been around each other since they were both old enough to wander round properly.
I was wondering if it was normal for kits to be so close and if it matters that she was an only kitten
Will they be so close when they're older as the people i know with 2 cats says they often sleep together but thatâ€[emoji]8482[/emoji]s about it, but they both have one social cat and a shy cat, whereas both of mine are very sociable. Does it make a difference?
Also, sometimes Archie growls a bit at Tilly if they both want a particular toy. Its rare, and she never seems fazed by it but should i be worried and can i do anything to stop him?

Thank you, kas

This all sounds perfectly normal to me. It is very sweet, and a wholy positive thing that they are so attached to one another.

Don't worry about any of it a bit.

You don't need to do anything to stop his growling. It's normal. BTW, what's a "half sibling" in a cat?

Are they related then or what do you mean by half-sibling?

Are they both spayed and neutered? Playful sibling kittens turn into playful sibling kittens with inbred kittens of their own if not fixed Just checking.

I wasn't worried, just unused to cats that actually like each others constant comapny.
By half siblings i meant same daddy, different mummy's. A cat can have half siblings right? Or would you not bother? I just call them brother and sister to save time.
My cuties will be s/n as soon as they turn 5 months which is the earliest my vet will do them. I wish it was earlier though. Is it ok for Archie to be s/n at 5 months and a week so he can be done at the same time as Tilly? Or should he be fixed at the earliest chance i get? I want to do them both at the same time because otherwise Tilly will miss him and cry the entire night! Plus that way they'll both be feeling a bit worse for wear at the same time.

Tilly, about 5 mins ago. Archie wouldn't stay still for long enough.
http://s54.photobucket.com/albums/g9...gAnch=imgAnch1

My vet lets me bring my cats in in pairs, even if one of them isn't having anything done, just to keep each other company.

Originally Posted by cata_mint

...By half siblings i meant same daddy, different mummy's. A cat can have half siblings right? ...

Click to expand...

Yes, that's what I thought you meant. I always thought that only kittens in the same litter are considered siblings, because it's more the rule than the exception to have different combinations of mothers and fathers from one litter to the next. But maybe someone who breeds cat will pop into this thread and set us straight.

My vet always keeps them together. When Archie has a bad reaction to his kitten jabs she kept them both in to stop Tilly crying. When we left she was wailing, and had loudly miaowed through the entire checkup/jab/microchipping for both her and Archie (who looked very worried when his turn came around).

When we came back we could still hear her miaowing. I asked the vet if she'd been like this the entire time, expecting an 'at first but eventually settled down etc' answer but instead got a very certain "yes!" from our harassed looking vet! Poor woman, I felt really guilty but she did offer to look after them both.