Are Siamese guard cats?

by Rebecca
(Il.)

My Siamese Cat-Tabitha, is extremely cautious. Not sure why? She is overly social and friendly to people who stop bye. W/me she is sweet but sometimes standoffish? Ummmm??? I have noticed that she watches me constantly as almost a guard cat.
Is this part if their traits? Yes, she is highly intelligent and exceptionally chatty!
My –Big question is; why is she always watching me and always at my side? She is defiantly not a lap-cat or enjoys being held, but I do see the loyalty and feel the love.

Thank you much!
~MEOW!”