While your second child may miss going to his daycare for a little while, hopefully this new nanny can fill in some of the blanks for him during the day.
If she drives, I would encourage her to take your son to many kid-friendly venues during the day as well as some toddler classes if feasible.
Another nice thing would be if your son can be involved in some play dates too as well.
I am quite confident that in no time your second child will adapt well to his new situation.
