
First welcome Hayley & Millie
Millie's reactions to other dogs is not unusual in puppies brought up in household without other dogs
Millie will only have seen other Weims except at the vets in all likelyhood, so every other dog is an unknown animal !
I think this is why some vets run puppy parties(not that I approve of them unless they are structured & controlled)
This is were training clubs & ringcraft clubs come in, even if you are never planning to show in breed or obedience. if you can find uch a club in your area pop along without Millie chat with the trainers & watch the class & if the methods are kind & the dogs happy enroll. I do breed showing & obedience train all my dogs even though they may never been shown or compete, as it all helps to socialize puppies
We also encourage people to attend our dog club as soon as possible & I confess my puppies attend before the vets advise, but they are in a crate or on my knee watching the class(unless there is a known illness doing the rounds)
Do not despair if you have any friends or relatives with gentle adults take Millie to see them or even get them to visit you one at a time. I have a GSD who is wonderful with puppies & it means my cavaliers are fearless of big dogs whne they meet them(does mean they also think they are GSDs as well tho' :D) Failing that the lady you met with the Yorkie etc might be willing to help you ,
Once Millie realizes that there are dogs other than Weims she will be fine
One word of caution do not comfort her when he does bark at other dogs as this will mean you are indicating to her that it is alright to worry & be afraid, however do reward lavishly if she doesn't react or is friendly & greets with puppy bows etc
The Perfect Puppy by Gwen Bailey is a brilliant book to read