I think that you are falling for the Irish Jedi's words. He used exactly the same word that you have used..."meek". Could it be that you, too, are falling for his mind tricks or is your choice of words merely a coincidence?
In all the episodes where Suzie has had better ideas (and her PM has ignored her), she has stated quite clearly that she is not happy and what should be done. In both the episode where Jim was pitching to the magazine at too high a price, she stated very clearly that they should slash their prices. She said the same thing after the 1st and 2nd pitches. Unless she put a gun to Jim's head, there was nothing else she could've said.
When the magazine name was decided, Suzie was quite explicit and made it clear that she did not like the name, HOWEVER, if the team decide to use the name, she would support the decision.
When the young white female was the PM (I honestly can't remember her name), and they were deciding on what price to quote the customer who wanted them to get rid of the furniture, Suzie was the only one who suggested that they should offer to pay the customer to take the office furniture. Suzie made this very clear. The PM then ridiculed her. The other team-mate (the black lady), was asked by the PM if she was doing the right thing. The black lady confirmed that they should charge the customer money and that basically Suzie was talking nonsense.
After the inquests, it turned out that Suzie was correct in all of the above instances.
After you have given your PM your opinion a few times, there is nothing else you can do. If you keep harping on about it, you create disharmony and argument.
I agree that she could be more forceful. However, I wouldn't say that she was totally weak, as is being made out. She gives her opinion and it is up to the PM to either take her advice or ignore it. So far, every time the PM has ignored her advice, they lost the task.