Normally in Ireland a relative who has been living with a tenant is able to take over the tenancy if the tenant dies. Local authority practice in Ireland varies on this; some will require the relative to have lived in the house for a minimum number of years, others will only allow the relative to take over the tenancy if the housing is suitable for their needs.
Since many housing associations are relatively new, not all will have established policies on this. If you are a housing association tenant, contact your housing association.
Contact your local authority or housing association.