It's not pushing her aside, it's just not acquiescing to whatever she says or wants. Doing that would just make them her puppets, besides it's her decision to remain hidden and work in the shadows.The three of them are working in concert to potentially save mutantkind and have been for well over a decade, I don't see her turning on Xavier and Magneto because she feels slighted or ignored. That would be beyond petty and disrupt long term plans they've made.