Just Shut Up and Nod
Look, we’re not saying that you, as an employee and subordinate, shouldn’t voice your opinion when your superior is talking. However, perhaps on your first week on the job, try and learn the system before you speak condescendingly to your superiors. Just a suggestion.
The OP was in her place to teach the new hire how to make cables because, well, he had just started his job. If you really wanted to impress her, you could’ve let her finish giving you the standard introduction and done a good job at making cables. Also, odds are she knew that you used to make cables at your old job, which is why you’re working under her now.