Sibelius 7 needs to be able to see Kontakt Player as a Kontakt device Type, not a VST. In order to do so, you need to be running Sibelius 7.1.0 or 7.1.2.
I looks like the rest of the setup is good, just update to Sib 7.1.0 or later and you should be golden.
I looks like the rest of the setup is good, just update to Sib 7.1.0 or later and you should be golden.