Well, their relationship might start off on a rocky note. Sakumo might be a bit skeptical about Fem Naruto's motives for being in the past. However, as they start to travel through different events in the past, Fem Naruto's determination and her kind heart start to win Sakumo over. They could start to have deep conversations about the future and the past, and how things could have been different. As time passes, Sakumo might become very protective of Fem Naruto, like she was his own daughter. And Fem Naruto would look up to Sakumo not just as a powerful ninja, but as someone who truly understands her and her situation. They could also work together to try and make the future better by changing certain things in the past, which would strengthen their bond even more.
At first, they might be a bit wary of each other. Sakumo doesn't know what to make of this strange girl from the future, and Fem Naruto is in awe of the famous Sakumo. But as they face challenges together during their time - travel adventures, they start to rely on each other. Sakumo begins to see Fem Naruto as a symbol of hope for the future, and Fem Naruto respects Sakumo more and more, seeing him as a father figure of sorts. They could also bond over their shared experiences of being different in some way. Fem Naruto is different because she's a girl in a world that expected a boy Naruto, and Sakumo was different in his own time due to his unique abilities and the way he thought about things.
Their relationship could develop into a mentor - mentee type. Sakumo, being an experienced ninja, could teach Fem Naruto some old - school techniques that are not common in her time. In return, Fem Naruto could show Sakumo some new ways of thinking, especially those influenced by the more modern ninja world she comes from.