Hi clairejo1984 and purple star ... it is strongly recommended that you each have an EHIC, but whether or not the card is absolutely essential very much depends on the terms of your travel insurance policy.
Travel insurance is vital, but in some cases it is a condition of the policy that you first try to obtain free or reduced cost treatment under the EHIC's reciprocal healthcare arrangements, before using your policy to obtain treatment. You would have to check the terms of your policy to verify if this is the case for each of you or your partners.
You are in the wrong forum for EHIC discussion, so if you require further information or contact details for the EHIC helpline
please click here.
David