Yes, Blac Chyna will help Rob overcome his nervousness because she will offer the support he needs. It is important for everyone to have someone to depend on. For Rob, Blac Chyna will be that person. It is difficult to feel nervous in public all the time, but it is easily overcome.
Having an outgoing girlfriend who is supportive can help anyone start to overcome their shyness. This is likely to be just as true for Rob Kardashian and Blac Chyna as it is for any other couple. If she is supportive and helpful to him, he will learn and change in the ways he needs to grow.
Regardless of the fact that Black Chyna is probably just with Rob to get her additional 15 minutes of fame, he does seem to be perking up and getting less reserved and introverted around her. It will never last, but for the time, she seems to be what Rob needs.
No, Blac Chyna will not help Rob overcome his nervousness because she does not have his best interest on her mind. She thinks only about money. She have a nasty language, she is aggressive and not well educated. With that kind of characteristic she is pushing Rob deeper in the shadow. She is cheaper version of Kardashian sisters and she is doing exactly the same thing that his sisters do.