In the novel The Buried Age, we follow Picard for several years between his command of the Stargazer and Enterprise-D. During his life as a civilian, he works with Janeway for a while. She's a lieutenant at the time. After accepting command of the E-D he considers possible first officers, and he considers her for a while, untill realizing she's unavailable.
Nothing about that novel is canon, but it was a very good read AND the idea of Janeway and Picard as XO/CO combo is interesting.
Nothing about that novel is canon, but it was a very good read AND the idea of Janeway and Picard as XO/CO combo is interesting.