Obviously Tuvok, mental illness aside, and other Aliens who age at a different rate count differently, and Janeway might have to have removed the mandatory Retirement enforcement that the entire crew of Enterprise received at the end of Star trek 6, and she might have shifted the line in so that the actual birthday which was supposed to become a choice for voluntary retirement was to be ignored. Kim in his 90s still trying to get promoted to Lieutenant Junior grade, but Captain Naomi Wildman just laughs at him, but how long would Janeway persist as Captain into her 70s and 80s and 90s and still be decades from the final leg of their journey?
Beyond simply allowing crewmembers to have children, Janeway should of encouraged it. Along the way, especially as the orginal crew aged, they could begin the recruit new crew from planets they stopped at.
They must have been doing that anyway given that the crew compliment never changed yet we know crew members were KIA.
New recruits would've been way more interesting than the Borg children. Of course, this tactic probably would've suited a Maquis ship rather than Starfleet. (They are pretty uptight about their rules & regs)