Attorney garnishment of wages?

Hi, I just received a notice in the mail from a local attorney regarding a debt from one of my childrens' parochial schools from nearly 4 years ago. At the time, I was unmarried, had different last name and address than I do now. This notice is for a debt in the amount of $350. My husband is the only one with an earned income. He's collecting unemployment in the amount of $149 a week. I also get $180 a week in child support. Is this attorney able to garnish a bank account (in my husband and my name) or either of these forms of wages if the only info they have is related to my former "maiden" name and former address? Would they be able to connect my maiden name with my new married name? Also we have 4 children, how much of our $1,316 a month income will they be able to take? Thanks!