as stated in MANY states its illegal to sell/give away/buy a puppy under 8 weeks of age.
this is in part due to health issues, a puppy goes through a high stres period in the 6-8week range where things just stress them out more than they normally would, a big move and change can in trun conpromise their immune system, and COULD lead to them getting sick easier.
the other propblem is, puppies do not realy start learning bite inhibition and socila play untill the 6-8 week mark, by removing them from their littermates at anyless than 8 weeks your removing their chance to learn from thier mother and siblings about what play is too much, as well as important dog to dog socilization skills...
its been well documented that while many puppies removed early do ok, puppies removed EARLIER than 8weeks are more prone to get in dog fights, have socilization set backs and be generally either more timid with other dogs and people or too bold and dominant.
these puppies also tend to be harder to break of play biting.
that being said, the pups SHOULD stay with their siblings for as long as possible...
as a breeder, my chihuahua puppies do not leave here untill they are AT LEAST 10 weeks of age, its better for their development, by that time they are clearly displaying behavioural patterns as well as any tendency for hypoglycemia, they are eating well on theri own and are past both the high stress and high fear stages, and have at least 1 round of shots and multiple de-wormings with a strong immune system AND a strong sens of self...it also gives me time to start with basic training ie crate and potty training...
a RESPONSIBLE respectable breeder will not allow their pups to go home untill at least 8weeks of age, 10 weeks is however more common and a better age in toy breeds as it takes them a little longer to mature to the "ready to go home stage"
and all ive ever heard from people whove bought puppies from me is how wonderfully there doing, how easy to train, and socilize ect.
if i get a particularly shy puppy ill keep the puppy unitll 12-16 weeks of age to make sure that puppy is developed and mentally strong enough to withstand the stress of a move...
thats part of being a responsible breeder.
6 weeks USED to be "ok" now veterinary and behavioural studies are showing that anything from 8-12 weeks is MUCH better on the puppy!
and welcome aboard Ruby