If a co-worker or even you boss is trying to make you look bad,then you can't just ignore them.You should confront it.Backstabbing is something most people will have to deal with at a point in their lives.
I think the first thing to do is to actually figure out if you are a victim of sabotage and if so,who is behind it.One tricky thing about finding your saboteur is the fact that their actions are subtle.
Have a talk with the person.Give your colleague a chance to explain her action. That may resolve the issue.Maintain a professional tone throughout the coversation and cite evidence of your suspicion.
Be prepared for the backstabber to Deny so don't back down.If the two of you can't resolve the issue,alert your manager to resolve the issue.
You may go straight to the manager if you think that confronting the person won't solve the issue but a good rule of thumb is to do this only if their is a business impact e.g the deadline for a project was not met.If the backstabber*s end result has a negative impact on a business outcome,it is easier to make a case.This will not make your colleagues see you as a jealous,difficult person.