You should bring this situation up with your faculty contact (chair of the graduate admissions committee and/or potential research advisor) at each institution you are still considering. They may be able to work with you to either defer admission or to help you figure out a way to start now despite your family concerns. Also, FYI, you may be able to save yourself the application fees if you do decide to re-apply in two years: at my institution, our offers of admission are valid for 2 years. Even if a student declines our offer and goes somewhere else first, the student may choose to enroll at any time within the two years. However, our financial offer (RA/TA to provide stipend and tuition) is only valid until April 15 of the year it is made, so if a student were to defer (or to decide to accept our admission offer a year or two later) we are not obligated to provide financial assistance. However, if you have explained your circumstances, and if you are still competitive relative to the new batch of applicants, you are likely to still receive a financial offer in the year that you choose to enroll. The main point is to discuss this with each department now, so that they can help you (if possible) or at the very least understand why you are likely to apply again in a few years.