My family received green cards along with me, and I’d like to give mine up alone.

Generally, the green cards of other family members (spouse, children) who obtained their green cards together with the principal applicant are understood to remain valid. Even if a green card obtained under the EB-3 unskilled category runs into problems because the applicant didn’t complete the required employment term, we’ve seen many cases where this doesn’t affect the other family members — since each person’s green card was granted through their own individual review, there’s no reason for one family member to lose the benefit that was already granted to them.