Incomplete question. However, I answered from a general English perspective.
Answer:
It refers to the inability to provide what is necessary for something or someone that we possess.
Step-by-step explanation:
We can see the meaning of such expression from the point of view of someone who is speaking on behave of a group statingout his displeasure that they're unable to provide what is necessary for their own; which can either be a person, or a property.
For example, a father and mother unable to provide enough food for their family may say in a low tone, "we can't take care of our own," referring to their children.