Her birthday is in late October. She’ll barely be 35 by the point of the election in November, but she will still be 35. So, she’d be 35 both when elected, and when inaugurated. It’s a non-issue.

She was born October 13th, 1989. That means she’ll be 35 by the time of the election in November, not to mention before the inauguration in January (the date that actually matters). So, she’s definitely eligible.