Hi abbey. I guess it depends on 2 things really.
1. How much you value the opinions of your friends. Have any of them said the job won't last or criticised it in any way?
2. How you are enjoying your job and coping with the workload and colleagues. If your supervisor is happy with your performance do you think you will be happy to stay there?
If you can answer those points positively I would say tell your friends you were settling in and happy to work there. Well done and good luck :)
The manager should respect the normal chain of command and accept the good review given by your boss. I suspect you have a reservation about the manager? Just be polite when you speak to him/her, good morning/afternoon and a simple smile, answer any of their questions as simply as possible.