Hi Pamela! I am not a dog expert, but can offer some advice based on my experience with Lola.
Lola was extremely shy of people when we first brought her home at 11 weeks. I was so worried! She's now 8 months and still shy, but has made tons of improvement. You've already received some great advice. Puppy classes are key, as well as taking Daisy everywhere and anywhere. I had a trainer recommend that I take Lola to 5 new places a week so she would get used to different sights/sounds/people. Always have a bag of treats handy in case you run into a stranger that wants to say hello. Make sure you tell people to approach her gently & calmly, palm facing up. Its also good to have friends come over to your house. Make sure they approach Daisy gently or they can even ignore her when they first come in and let her come to them. When non-dog people would come over who I didn't think would be able to approach her correctly I would tell them to just ignore Lola. Eventually Lola would go over to them to investigate and they would give her a treat. If they were dog people, I'd have them sit on the floor with her and say hello calmly.
After puppy class, I took Lola to a basic obedience class, once she was fully vaccinated I took her to a park daily where a group of friends meet with their dogs [an unofficial dog park that seemed safer to me than the actual dog park]. Going to the park helped with her socialization with both people and dogs and was great because all of the people there know how to behave around dogs and all of the dogs are friendly and non-aggressive.
As others have said DO NOT feed into her shyness or fear or you will only make it worse. Then she learns if she's scared, she can rely on you to pick her up and she won't build confidence on her own.
I had to constantly work with socializing Lola and it did pay off. At 8 months I still have to make the effort to have her meet new people and go new places. I wish she would have come out of her shell a little more and be a more "typical" social hav. But sometimes you just have to accept your pup for who he/she is. I think some dogs are just naturally more shy....they have their own personalities like people.
I also think the more shy havs might be prone to separation anxiety. Maybe its their lack of confidence that makes them attach to their owner a little more than necessary. So make sure you also factor in leaving Daisy alone for short periods, working up to longer so she gets used to spending time alone. I really went wrong here with Lola. I was so focused on getting her out and socializing her, now she doesn't like to be left alone!
Good luck! Just be patient and all of your hard work will pay off in the end
ps: At least your breeder was honest with you regarding Daisy's shyness. My breeder told me Lola was the most outgoing puppy in the litter!