Relinquishment deed thru powe of attorney

We have already executed a partition deed and registered but relinquishment deed from my 3 sister's has not been obtained .My.sisters are very.old.now and.not able to present personally infront of the Registrar to sign on the relinquishment deed. In that case is it ok to appoint one General Power of Attorney for all the.three sisters in one GPA or is it necessary to make three POA document for three sisters Separately. Common power of attorney for 3 persons for relinquishment deed. Please inform Regards