Winifred Lawrence was a Federation Starfleet JAG officer on active duty in at least the 23rd century. In 2294, Fleet Captain Lawrence was the seniormost JAG officer assigned to the sector that included Starbase 29. (Star Trek: Avenger: "Belonging") Fleet captain is an unusual rank for a JAG officer, which is not a line officer billet. It's possible that she might have had line officer experience and credentials -- such as graduating from Starfleet Academy Command School -- before joining Starfleet's JAG Corps.