On her third full day in the United Kingdom to accompany President Joe Biden on his first G7 Summit, Jill Biden peeled off from her husband, and the rest of the program’s leader-spouse events, for a solo excursion of her own — one of several the first lady has taken while abroad that highlight the importance of emotional well-being. The event fell in line with Biden’s vision of her role on this trip, which involves a roadmap for life post-Covid-19.