1. You'll know if she's overeating, because her poo will be runny.
at that point I would stop "free" feeding and put a much smaller measured dose in the bowl.
2. As Al' says Oh, yeah you'll know when it happens.
She'll start getting little tufts sticking out and the amount of fur tumbleweeding around the house will escalate.
Then you should be grooming her every day and every day it will look like you've just sheared a sheep. Every day
for between 1 and 2 months !!!
Coat blowing can start as early as age 8 or 9 months or as late as 2 years. All depends on the dawg