I'm going to throw out a random guess for
Goldilocks Gardner (what were you saying about unimaginative names...?), which captures 'Blue Peter dog', 'secures the room' (locks), and 'she'. I can't make it fit the rest of the clue (unless 'Skcoliglog' rings any bells...?), but I'm not spectacular at these and may be missing something obvious.
I feel like there was also a Blue Peter dog named Bonnie. Bonnie+Door =
Gondor, if 'we hear' means something like 'sounds like'. And, um... Gondor is very clever?
?
(I guess backwards that would be 'Rodnog', which could possibly be valid Sindarin.)