According to this:
June’s choice to seek revenge on the villain of The Handmaid’s Tale, however, was not made easy. As her final words of the season indicate when she tells husband Luke (O-T Fagbenle), “I’m sorry. Just give me five minutes with her [Nichole] and then I’ll go,” she has potentially risked her freedom in order to further her war on the fascist regime of Gilead.
Bruce Miller, the creator and showrunner, explains:
She says, “I need five minutes” — she’s five minutes from a reckoning. She doesn’t want to think about it or talk about what happened or what this means for five minutes. Certainly, everyone has been there. “Just let me be who I was for five more minutes and then I’ll decide who I’m going to be next.” What the hell is going to happen in five minutes? It can go a lot of ways and, the answer to your question is that I know what’s going to happen for the next five minutes, but I don’t know what happens after that. I don’t know because June doesn’t know. I know how she feels now, and that will lead me to the next thing.
That moment at the end is her as a mother knowing she had chosen something that makes her feel like she can never be a mother again. She’s holding that baby and she’s thinking to herself this way, as a mother, and then she thinks of herself that way in the woods with dead Fred, and then she thinks of herself as a mother again and that’s where she is. Those two things are pushing up against each other. On one side, she is a mother and a caregiver, for Janine or her daughter or her friends or lovers; and then on the other side, she is a person who is getting vengeance for all of those people and for herself. You put those two things together when she believes, and I think we as the audience believe, that those two things can’t coexist.