The 1095-A probably needs to be reported on your client's tax return, but there are some things go consider first:

Are the kids the only ones covered on the 1095-?  Or are the aunt and/or uncle covered on the same 1095-A well?

Was there Advance credit paid (column C of the 1095-A)?

Were they insured after they moved back with parents?  If so, did they report that move to the Marketplace?

I know nothing about the situation, but you may want to double check that your clients can claim the kids.  For example, did the kids live with you clients for over half of the year?  If not, was the living with the aunt and uncle clearly a "temporary absence" from living with the parents?