I always heard that you should not label children because they will feel intimidated by positive labels and live down to the negative labels, so I tried really hard not to label my 2 shy children. My youngest son had a label applied to him by a preschool teacher, that he was shy. I remember taking a book to her to show her that his shyness was just a part of the normal spectrum of humans and I did not feel that it was anything to worry about. My daughter is even more shy and has a history of not making her own phone calls, not talking to strangers, or acquaintances (or even some family members!), just shrugging when asked most questions by most people, so that she has a reputation within church and family of being extremely shy. When they were little, I'd just say "He feels like he needs to stay with mama for a while" or "She seems to be feeling a little shy right now." to other kids who asked them to play or adults who wanted to include them in some fun activity, being careful not to label them as permanently shy, just saying that they were having a shy moment.
Now that they are 18 and 20, I don't think most people think of my youngest as shy. He will talk to people, answer questions and seems pretty normal. ;-) I don't worry about him at job interviews or anything like that in the future. I think he'll be fine, despite not talking to anyone outside the family for the first 4 years of his life. My daughter on the other hand, remains reserved, but is improving. Back in March of this year, we started selling our art and crocheted creations at a little shop in our town. The deal is you are supposed to work 2 days a month to get your full commissions. I figured I could work with her the first couple of times and then she'd be fine to work on her own, but she's still not fine and it's been 5 months. She doesn't like to greet customers and she is afraid the phone will ring and she'll have to answer it. She did get a job at a local preschool, mainly because I had gotten the interview, then been offered the other job, but still wanted to talk to them about working there, just in case ... so I took her along to the interview and presented her as an alternative to me, answered questions for her when she shrugged and basically was the worst helicopter parent in the world, only I was involuntarily hovering. I wanted her to do it on her own, but she wouldn't. I also went with her 2 of the times that she had to meet with them and fill out paperwork, (against my will) but then the third time, miraculously, she went on her own and she has gone on her own to work all 5 days this past week. Some things are just harder for some people. There is a range of normal and there are a lot of different personality types and they're all okay to be.