Was Snape helping Lily in Potions?

Question

I understand there might not be anything in the books to explain this, but I was wondering.

Slughorn repeatedly tells Harry of Lily's almost inspired abilities in Potions, while Snape, according to what he writes as the Half Blood Prince and the pure fact he went on to teach the subject pretty soon after leaving school, was clearly extremely advanced.

Considering the friendship lasted up to OWL exams, did Slughorn perhaps remember her being inspired up to that level and forget whether she perhaps fell back to relying on book smarts during NEWTs (which I think to become an Auror she must have taken)?

The description of Lily, while a great student, doesn't seem to suggest either the love, time or the pernickety dedication that Snape put into perfecting the subject, nor the unpredictability separating a student like Snape from a Hermione in terms of learning by experimentation over frequent journeys to the library.

So did Snape help her or was she just naturally talented at that as well? Or is it an impossible thing to answer using only the books as evidence? If so apologies.

We also know that Slytherin and Gryffindor students are taught together in Snape's dungeon, so it's possible, if not likely, both could have been in the same class.

Answer 1

We'll never know if Snape helped Lily at Potions, but every indication is that she was gifted at Potions on her own accord. Snape and Lily had a falling out in their fifth year, after Snape loudly and publicly called her a Mudblood. That would have left Lily two years of Potions without his help, plenty of time for Slughorn's opinion of her to change.

Instead, Slughorn tells Harry that Lily was "one of the brightest I've ever taught" (Ch 4, Horace Slughorn) in his decades of teaching. I doubt he would say that if she didn't a) go on to N.E.W.T. level and b) excel at that level as well.

But it's this line that stands out:

"That's the individual spirit a real potion-maker needs!" said Slughorn happily, before Harry could reply. "Just like his mother, she had the same intuitive grasp of potion-making, it's undoubtedly from Lily he gets it..." (Ch 18, Birthday Surprises)

That fact that Lily was known for an "individual spirit" and an "intuitive grasp" of the subject points to her being naturally-gifted, rather than ably-tutored by one of her peers. Of course, Harry ISN'T naturally-gifted, but I can't see Lily pulling the same scam in the same year, and likely the same class as Snape.