Child Interface with no methods

So I have an parent interface, and some other child interfaces, some have implementation, some others don't.

interface IParent {
    void A();
    void B();
}

interface IChild1 : IParent {
    void C();
}

interface IChild2 : IParent {
    // empty, just inherits
}

Is that good practice? If not, what's the better way to do it?