For pete sake 1980 Jean in the Dark Phoenix Story (before the Dark Phoenix event happened, but during the build up with this saga.) Kitty Pryde / Shadowcat is 13 and her powers just manifested and Storm, Wolverine, and Jean tried to recruit her to Xavier school. Well due to hijinks involving comics Kitty was gone not for a few hours but instead over a day and the parents were worried. So when Kitty finally returns home and the X-Men tried to recruit her, the parents rightfully said no I can't trust you. So what happens, how did Kitty join the school? Well Jean Mind-Control the Parents to change their mind and allow Kitty to attend.
Now this is one event, but there are dozens of other similar times throughout the decades of Jean stories.
My point is Emma Frost is an antihero who does both heroic things plus wicked / cruel things. Emma has been an antihero ever since Generation X (so 90s) where she lead that school and she had to come to terms with her Helions being killed by the Sentinels and she was in a coma for some time (and when she awoke from the coma she temporarily housed Bobby Drake and used powers Iceman could not use at that time.)
Jean Grey has always been a hero, but she has done some shady stuff in her 4 decades runs (with her being decade more than 2 decades but not in consecutive intervals.) Just because Jean is a Hero does not stop her from doing good and shady stuff she is capable of both, but unlike Emma she tries to [censored] her way around the issue in order to preserve her self-image inside of herself, and the self-image she presents to others.
There are lots of differences between the two, Jean and Frost, but there is no magic brightline between them, it is more of a spectrum that is a liminal zone. Liminal as in is the quality of ambiguity or disorientation that occurs in the middle stage between two events or between two extremes. (And all of this is okay, for humans are liminal creatures, especially heroes.)
But yeah read those comics I talked about earlier for Emma is a complicated character.