PP I just read that article and it seems that the deciding factor is that the insurer has the right to decide how an article can be repaired/replaced (specify a repairer or a retailer) provided that the insured person can get the entitled repair/replacement using the specified process. If they can't, then the insurer must deal with them in such a way that they can get the repair/replacement to which the insurance entitles them. If the person insured CHOOSES not to use the insurer's process, then the insurer is entitled to reduce the settlement by any difference that it would cost the insurer.
In the OP's case, it seems that she CHOSE NOT to receive direct replacements for her lost items; and also CHOSE NOT to accept the value in vouchers, therefore the insurance company would appear to be entitled to give her a cash amount equivalent to what it cost them to buy the vouchers. Sadly it seems that in this case, any sentimental value formed no part of the insurance cover.