I would say a big fat NO to those happy time correspondence!
Let's say you had a cut on your finger that was healing. Sometimes when you're doing every day thing like typing, buttoning a shirt, you realised you couldn't use that finger and you think gosh I forgot how much I relied on that finger...You just take it for granted. The pain hurt but you also remembered a tiny bit how much you needed it.
Then lets say someone shook your hand and squeezed that finger really hard and said see if your finger wasn't cut that wouldn't hurt. Or out nowhere they poked you right in the cut. And you think that really hurts.
That's what you're doing!! Yes you remind her that the relationship is over but do YOU want to be that reminder? Also you might think you're reminding her of the bad times but if she's ensuring that she's being stubborn about this all she'll do is reread that correspondence to find something she never liked or find something that underlines her decision.
