Raising two puppies at once is literally TWICE the work as raising one pup, because in order for them to form their own identities and not become dependent on one another, everything must be done separately -- crating, walking, training, playing, etc. The more time they spend together as youngsters the closer they will bond to each other and therefore the less important you will be in their eyes. In order for them to become loyal and well-behaved adult dogs, they need to form a strong bond with YOU while they are young.
It can be done, but it will not be easy... especially when you've already got a 3 year old child to care for as well!

Good luck!
Here are some older posts about raising two puppies at the same time, as well as a few internet articles regarding "littermate syndrome":
Stan Rawlinson explains the problems of rearing Two Pups from same litter
Raising Siblings
Please help - one or two puppies??
Raising littermates - any experiences??
Is it sibling rivalry??
Can I ask why the breeder gave the female away for free? Is she deaf?
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Zoë
Creek - Fawn Female, born 03/23/2001
Caney - White Female, born 03/27/2007
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