The last thing which Lady Lysa Arryn sees and hears in her old life are Petyr's face and words.
Well, the absolute last thing she really sees is the stony ground on which she ends her life in the Year 300AC.

She ends her life with hate, her whole heart is filled with hate on Petyr.

Then nothing...

And then she wakes up again fifteen years in the past.
Saner, younger and hateful.

...
King's Landing 285 AC

It takes her five days to figure out what exactly had happened with her, that her first life had really happened and that she had not just woken up from a very horrible long dream and to then calm down enough to face her new reality.

She locks herself in her rooms near those of her husband for these five days, screams at everyone to leave her alone for awhile and then speaks to no-one for the next few days , she doesn't eat and only sips a bit of Water.

Her mind had woken up in her younger body, her fifteen years younger body and her mind remembers everything from when before she had died but also remembers everything to the minute of this fifteen years younger body.

She calms slowly down during the days after her first shock, she examines her younger, prettier, slimer body and when she finally opens the door after five days, she is ready to live her second live to the fullest, to grasp this second chance with both hands.

Only that her second life is not really different from her old life, it is just that now she has knowledge of things to come and the absolute hate towards Petyr in her heart and mind.

It is this hate which convinced her the most that this was a second life, for she had never before felt this hatred about the man who had fathered her first child in her.

The first child which her own father had killed years back in her womb, but that was really something about she needed to stop thinking right now.

Now she needs to think only about how to change her future to the best and that is not exactly easy to begin with right now.

She is already married to her dreadful old husband for a couple of years now, she had already had miscarried one of his Spawn and she remembers all to well how long she had to endure him, how often she had miscarried in the years to come till finally Petyr planted her sweet Robin into her womb and her sweet sweet boy then grew up as falcon heir.

She must not think about her sweet boy, she reminds herself that she really must not, that she must forget her sweet son for she cannot and she will not ever lay with Petyr again, not in this life.

The problem is though, that she wants to have children, she really wants to be a mother and she long now had figured out already in her first life that Jon Arryn's seed was never able to get healthy and alive babes on any woman at all.

No, Lysa thinks now to herself as she sits opposite of her old husband while both are having a late meal together, no she will have to look elsewhere for some strong seed to give her healthy babes.

She forces herself to smile at her husband and thanks him in a demure voice for giving her a few days of solitude and peace in this busy atmosphere of the Red Keep.
The old fool blinks at her with surprise because her unusual smile and then he just nods and speaks about the fact that he knows that her miscarriage with his child was just two moons ago but that that they both would have to try anew for the much needed Heir.

Lysa swallows once, forces herself to smile brighter and agrees fully with his wishes.

And tomorrow, she promises herself as she later lays under her husband's wrinkled body, tomorrow she will look for a real man to give her healthy children.