H4 I-94

H4 is valid as long as you are in H1 AND H4 I-94 is not expired. If H4 file extension with you, then H4 will get another I-94 (attached with I-797) that will have a later expiration date. So, extend H4 with your H1 unless that current H4 I-94 date still good for, say at least one more year.