Forum:Why didn't they?

In first year, Hermione used "Petrificus Totalus" on Neville Longbottom to prevent him from stopping Harry while he was saving the Philosopher's Stone. Why didn't she use Petrificus Totalus on Lupin when he turned into a werewolf in POA? Why didn't she use it on Pettigrew while he was running away? There are many examples of places Petrificus Totalus could have made things easier for the trio, so... why didn't they use it?