Not necessarily, but that is also an option. Give her a good rest, kindness and care, or give her an unlimited credit card and a week in a mall, buy her a rejuvenating treatment in a wellness spa, or just make her feel herself like the Queen of the World when she expects but trouble after a tiresome day. These all will do. ;)
This made me think of the children's book by Mary Rodgers, "Freaky Friday" (subsequently made into a Disney movie), although that's more about a teenager who wakes up in her mother's body! However, her mother also "borrows" her body for the day, so in that sense, it could be said, "the lady is young again". It is a somewhat strange sentence though - might make more sense if it was "the lady FEELS young again" or something along those lines.