He doesn't have to be on the grounds to tell Dumbledore whatever it is he knows about Clover.  "I would be much obliged."

He grins.  "I'm happy to help.  I'm sure you and Father will get along splendidly."

Smile.  "I did meet him once in Diagon Alley, did I ever say - "

And she can lapse into the kind of small talk people-not-Maledict do when they like each other.  (Even in Slytherin, apparently.  ...Okay fine maybe the Hat had a point about that.)

She spends another evening thinking.

With Whitlock and Malfoy both on her side, she might be able to oust Snape from Hogwarts completely, but if Snape belongs to Dumbledore, Dumbledore might still listen to Snape if Snape ever tells Dumbledore his suspicions about Clover.  Indeed, he may have already done so, and even if he hasn't he'll have plenty of time to do so before Clover gets him sacked.  It's still obviously better for her not to have Snape around, but in the meantime she has to do something to make him less believable.

How can she convince Dumbledore, even against Snape's evidence, that she is not Maledict Gaunt?  What would Maledict Gaunt, in her situation, find so unutterably unthinkable that she would scorn even to pretend to do?

The answer comes to her at once: go to Dumbledore, tell him she fears there is something of Maledict Gaunt in her, ask him how to kill it.

But then, one of the reasons that Maledict Gaunt in her position would not do this is because it would be fabulously stupid: here are the ways I am suggestively similar to Maledict Gaunt is not a good opening line for convincing someone you are not Maledict Gaunt's reincarnation.

...Then again, if the woman she is reincarnated from managed to live both as Maledict Gaunt, master of the Death Eaters, and Dumbledore's friend and ally Tamsyn Riddle... she could probably thread that needle, in the fullness of her power as a deceiver.  Could she, Clover, the shriveled child-thing she has been shrunken into, do the same?

She wouldn't want to bet on it.

So what else can she do to - 

- to discredit Snape.  Hmm.  Could she convince Dumbledore that Snape is irrationally prejudiced against her?  What reason would Snape have...?

Didn't Bill talk about how Snape used to be really nasty, before McGonagall and Dumbledore set him straight, George Weasley had said.

There were complaints about his behavior towards some of the students when he was first hired, Whitlock had said... Until now it had seemed that he was able to - meet a minimum standard of professionalism. I'm sorry that we the staff were wrong about that.

Could she dig up information about Snape's past misdeeds, try to present Dumbledore a students-eye view that suggests he's slipping back into old patterns?  Or convince other staff of the same, go to Dumbledore with them as backup.  Whitlock seems sympathetic already... if Clover remembers correctly she's a recent addition to the staff.  McGonagall she's made inroads with already - 

Hmm.  But she recognized McGonagall the first time she saw her, and McGonagall was struck by her as well; one or more of her past-life identities might have been close to McGonagall.  It might be risky to try to get close to McGonagall, give her more inspiration to foment her own suspicions to match Snape's.

But Lupin had also reached out to her, and didn't seem to trip any past-life memories doing so, and looks the right age to have known Snape in school as well.  Hmm.

She takes the scroll and unrolls it.

From Lucius, Lord of the House of Malfoy, to Clover Evans, Scion Heir and Lorde soon of the House of Potter:

Warmest salutations.

My son Draco spoke of you in his last letter to me.  He tells me that I made a good impression on you when we met in Diagon Alley, which I was honored to hear.

I was sorry to hear about your troubles with Wardwizard Snape.  My son tells me that many of the staff were willing to speak to him, and to the Headmaster, in your defense, which is a credit to the school; but certainly Headmaster Dumbledore seems inordinately fond of the man.  I have heard unsettling rumors regarding his past behavior to students.  It is difficult to rally the Hogwarts Board of Governors to any positive or productive action, but if other members of staff are willing to speak up and corroborate your story, they could be made to see reason.  I don't wish to make any promises, but it is certainly my own opinion that a man who behaves as Snape has behaved should not be employed at Hogwarts school.  If you wish to file a formal complaint, as is your right, then you will have my support, and if I can assist you I would be honored to do so.

On a lighter note, my son also tells me that you're taking an interest in recent wizarding history.  To discover the world of your birth, full of things undreamed of in the mundane world, for the first time at age eleven, must be a dazzling and overwhelming experience.  I don't wish to be presumptuous, nor overly familiar, and I certainly don't imagine that I could fill the void left by the tragic loss of your family, but I would be honored if you would let me help teach you about your history, that of your family and of Magical Britain, and about navigating the world you have entered into.  The Malfoys are in your debt, and it would be the least I could to do begin to repay it.

I implore you to reach out to me with any questions or concerns that you have.  My owl Eltanin will remain in the Hogwarts Owlery for a day if you wish to respond immediately; but if you are delayed, any Hogwarts owl will know where to find Malfoy Manor.

Yours,
Lord Malfoy