回复：补充说明，以免误会：加拿大，还是墨西哥？？？

file I-539 now to extend H4, pay one fee for all H4s in your family who entered together with your spouse, (and given the same I-94 expiration date)


They could have gotten the I94 expiration date of your new H1 I-797 if they had showed that at port of entry.