母亲是加拿大移民，但最近刚收到美国移民批准信，绿卡要3个月收到，但由于健康原因马上要回加拿大看病，现在马上申请返美证行吗？同时拥有2个国家的移民有问题吗？
-She needs to bring the I-485 approval notice and passport to the local USCIS Office to get the green card stamp for travel if she leaves US before she receives the approved green card.
-She needs to bring the I-485 approval notice and passport to the local USCIS Office to get the green card stamp for travel if she leaves US before she receives the approved green card.
