What she means is that she had made 19 trips to Maryland, helped 300 people to freedom, yet she was never captured and didn’t fail to deliver her "passengers" to safety. As Tubman herself said, "On my Underground Railroad I [never] run my train off [the] track [and] I never [lost] a passenger." During these journeys she helped rescue people that were from her own family and people who weren’t from her own family. You can check her story in the America Library.
impossible to subdue or defeat; cannot be overcome
You should start off with talking about an few female athletes that are famed around the world but don't make it too long.
