What is the best time for my child to take a nap?
What is the best time for my child to take a nap? How long should it last?
The best time is the natural time. If the kid self-regulates on a daily basis, there is no issue. If you had done some "planning" before, she may need some assistance to rediscover her natural needs. For a little baby, all intervention and planning are not welcome. For an older kid, it depends on the stage of brain development. It depends if the kid takes two naps or just one nap per day. Once the kid settles on one nap per day, you can use the adult rule of napping: the 7th hour from natural waking. See: Best time for napping.
The duration of the nap is easiest to establish: don't wake the kid and you will find out the optimum duration.
To learn about complexities of early napping, read Baby sleep.