She voluntarily let Galactus try to remove the Phoenix, basically because she figured she could not beat him or that she could not beat him AND save her friends and Earth in the process. Galactus admitted the Phoenix was a threat to him, which is why he planned to separate it from it's host. Eventually, Roma, Uatu and Death (in the guise of a mustached man) persuaded Galactus that he must not proceed. It's in the scans, but they didn't come out as big as I planned.
@bag_o_x_men An elbow is an excellent option, one of my top four choices. How is getting someone bleeding not a good thing for strategy? That sounds like typical headhunter mentality. You don't need to knock people out to win fights.