Get in contact with her.
Keep in contact with me.
We are out of contact with each other.

都可以，你会理解的。我使用“touch”或“contact”。我更多地使用“contact”与我感觉不太亲近的人，例如：工作环境或学校环境。我和朋友更多地使用“touch”。如果朋友搬家，我会告诉他们“Keep in Touch”。如果我在学校做一个小组项目，我可能会说，“Get in contact with me, so we can decide when we both have time to work on this.”