Benjamin Seaver (1791-1825) and his wife Abigail Gates (1797-1867) had four children, and I wanted to add them one at a time to the family.
In the [People] icon screen and the Family view tab (which shows the pedigree chart), I can add a Child by clicking on the "Add Child" field below the word "Children" in the Family panel below the pedigree chart (see screen below):
When I do that, I can type in the child's name, and when I click Enter the input boxes for that child opens in the right-hand panel. I can add the birth, marriage and death data for the Child, as shown below:
a) I could go to [Person] in the Menu line and click on "add Person" and then click on "Add Child" and a box to enter the Child's name will open.
I much prefer using the [Family] view screen method to the [Person] screen method to insert a New Child to a Family. Unfortunately, you can only do one child at a time (clicking New Child), rather than put all of the children and their birth and death dates/places in by a series of keystrokes and tabs (like in earlier FTM versions). When you're done with the first Child, then you have to click New Child to add the second Child.