I think it will help, but w/o knowing a lot more about you and this person, it is really hard to say how much – maybe a tiny bit (they read your applicaiton even more closely), maybe a moderate amount…I doubt a second degree connection will ever be anything close to automatic, though.
Taking hardest rigor is super helpful…and I agree with others that GPA is more contextual than a lot of people seem to realize. There are places a 3.75UW is top notch and other places it is “above average” and AOs can glean this from school profile, recommendations, etc. Ivy admissions seems to have time and resources to take this into account.
Anyway good luck, do your best on your essays and application and build a balanced list like you would anyway!