I try to keep it equal between my two kids. DD’s school was $20k/year more expensive than DS’s, and she took longer to finish, but he has had some expensive fender benders and other expenses.
I have one friend who makes good money and so does her DH, but it annoys her no end that his parents shower big time $ (like buying a $800k coop) on his sister who has a career in the arts and doesn’t have a pot to piss in. She feels like he’s punished because he’s self sufficient.