You must be separated one year and one day before you can file for absolute divorce. Divorce from Bed & Board is a formal way of stating that the spouse no longer lives there. If she has in essence abandoned you and your child, then you should set up a consult with an attorney. She would still be entitled to 1/2 the marital assets unless you can get her to sign an agreement stating that she does not want any of those assets. My suggestion is to get to an attorney, get a separation agreement drawn up so that you have primary physical and legal custody of your child, you retain the marital home and your retirement and request child support. Unless you both make the same amount of money, one of you will pay the other child support. Normally it’s the parent with primary custody that receives child support.
Document everything you can think of, date that she left, instances that you have spoken with her and what she has said. Consult an attorney to see where you stand. If you can get to the one year one day mark without her asking for equitable distribution of marital assets or with a signed agreement then you are pretty well set.