how do i introduce lab puppy to two two and a half year old labs (dogs) the puppy is a girl...

i am no expert but i do have several dogs and recently bought a new puppy, well i introduced my yorkie girl  (sheis 6mounths now) straight away into the pack i also had a pen available introducing her gradually and they seemed to like her ,1 of them justs ignores her though as if to say im the baby here.i have 4 yorkies 2 boys 2 girls and they all get on  .
hope your introduction goes well too