The court looks at the best interest of the child Family Code 3011. Your ex can not just move with the child, she is going to have to file a Motion.
The court is going to look at why the mother has moved the child so much in the last 5 years and what the purpose of the requested move is. Is the move motivated by bad faith, meaning is she just trying to keep the child away from you and is the move in the best interest of the child.
You will need to show that the move will be a detriment to the child. The courts encourage a relationship with both parents so your emphasis must be on the child.
I would contact an attorney in your area for assistance. Child custody//visitation is not an area to go Pro Per in. You need a Family Law Attorney.
Note this answer does not constitute legal advice, and should not be relied on. Each situation is fact specific and court specific, and it is not possible to evaluate a legal problem without a comprehensive consultation and review of all the facts and court pleadings filed in the case. This answer does not create an attorney-client relationship
You need to file an Order to Show Cause immediately to stop her from moving. You should discuss this matter with a local attorney because you might need emergency "Ex Parte" orders to stop the move because a normal court date is beyond the 45 days.
Act now. Do not delay. Talk with an attorney as soon as reasonably possible.
If you wait too long the court might not look at it as an emergency and set it for a normal court date after she moves.
The other attorneys really hit the high points on the legal issues surrounding the move. The other issue is where your case should be. Since you now both live in Santa Clara County, you might want to also include a request to move the case to that county. Again this probably requires hiring a family law attorney.