BROOKLINE, MASS. — Shanta Farley used to be a preschool teacher, but now she has chosen to stay home full-time with her two-month-old son, Conner."When I was teaching, I noticed that the teacher really became the primary caregiver to a lot of the children who were there from 7:30 in the morning to 6 at night. I felt there were so many things I was seeing that the parents were missing out on. I think that's my main reason why I decided to stay home," she says in an interview at her apartment. "In the first year, [Conner] is going to sit up and start to walk and start saying little words. That's so much compared to the later years, and I just don't want to miss any of it at all." Though Mrs. Farley spent two years getting a master's degree in early childhood education, she decided to put her career on hold. "It was a hard decision, because I'd gone through all that work, and I really wanted to get going." But she says she will not return to full-time work until Conner is in kindergarten. Her husband works for a computer company, and "finances are not a big problem for us right now." But someday, she says, they would like to own a home, and "once we make that move, I may have to get a part-time job." "I'm lucky I am in a neighborhood where there are other young mothers," she adds. "I don't know what I'd do if there weren't many around. I'd really feel isolated, which I know happens to a lot of people. "The only thing I'm a little concerned about is, after being out of the work force for a while, how it's going to be to go back." Meanwhile, Farley looks forward to taking recreational classes with Conner, such as "Gymboree," a parent-child exercise program. "And after he turns three months, we can take swimming classes," she adds.