[Corin Stormhands]

Actually, she covers the "remember my last" part in Book 7.

Except for the fact that a letter came with Harry when he was dropped at the Dursleys. Right?

Or am I misremembering?

[GraceCoolidge]

You remember correctly. Dumbledore explains Harry's situation in a letter to the Dursleys when he drops off the baby at the house.

I was surprised that there was nothing else in the book re. Petunia's childhood correspondence with Dumbledore. I also was surprised that apparently some contact remained between the sisters, as Lily refers to baby Harry breaking a vase that Petunia had sent to Lily for Christmas. I had the impression that there was no contact. I also wonder what happened to the Evans parents? Lily was 21 when she died, so they probably were not that old, yet it seems both must have died.

[SuziQ]

No, Corin, you're not remembering incorrectly. "Remember my last" refers to the letter Dumbledore left with Harry on the doorstep, telling Petunia she needed to care for her sister's son until he came of age.

The letter Petunia sent to Dumbledore would have been long before Harry was ever born.

[r9etb]

Except for the fact that a letter came with Harry when he was dropped at the Dursleys. Right? Or am I misremembering?

No, you're right.

But a lot of folks have wondered why a howler from Dumbledore, saying "remember my last," would affect Petunia as it did. "My last" seems to imply more than one letter was exchanged between them. Book 7 fleshes it out a bit more: she had actually corresponded with Dumbledore before, begging to be "taught" magic. It helps to explain why Petunia was affected more than perhaps she ought to have been by a seemingly cryptic message.