Too lazy for Google huh? Well, let me tell you the tale of ol' Franky. Franklin Richards is the son of Reed and Sue Richards of the Fantastic Four, (Mr. Fantastic and the Invisible Woman respectively) and is THE most powerful being in the marvel universe by a long shot. For scale, in the Marvel multiverse, there is a being known as The One Above All, who is the in-universe representation of the will of the writers of Marvel. He sounds pretty strong, right? Well, Franklin kicked the shit out of him, so there's that. Other ludicrous feats include: making Galactus his herald, using his omnipotent reality warping abilities to make himself even more omnipotent so he could beat Onslaught, and casually obliterating Mephisto.
Rachel Summers is the child of Jean Grey and Scot Summers (Cyclops) so you know you're in for a ride. First of all, she has both their powers, so that's cool. She not only has access to the entirety of the unreasonable power that is the Phoenix Force, but also managed to beat it into submission with her mind. By the way, the Phoenix force is actually a living, sentient creature, of which Galactus is terrified. She once went and solo'd Apocolypse, who is one of the most powerful non-abstract beings in the Marvel universe.
So, yeah, pretty Op. I would say that Marvel should nerf them, but that didn't go over so well last time.