I'm not sure the insurers would pay out for the unused flights as they have already paid out for the hospital bill in Turkey and for the cost of flights to repatriate us back to the UK. I have no quarrel with the insurance company - they were great.
I'm sorry to hear of your sad loss.
Am I right in assuming from the above that you haven't yet checked with your insurer about whether they would re-imburse you for the flights back home that you are now unable to use because your trip was cut short on account of your partner's ill health? Given that they did take care of you and repatriate you early they clearly regarded that as a vlaid claim within the terms of your insurance policy so I would contact them and explain the position. Like Shirley, I would have assumed that they would cover you for this but you won't know if you don't ask. Give them a try.
maybe they would let you change the flight date to use perhaps next year
Or give you a credit note that you could use for a future trip when you feel ready?