I HAVE LEGAL AND PHYSICAL CUSTODY BY A COURT ORDER IN PENNSYLVANIA. HER MOTHER WANTS TO COME FOR A VISIT TO CALIFORNIA. CAN SHE KEEP HER IF I LET HER GO BY HERSELF. SHE IS THIRTEEN. THE MOTHER AGREED FOR ME TO HAVE CUSTODY A YEAR AGO. CAN SHE JUST CHANGE HER MIND WHEN THE CHILD GETS TO...