Pictures of kids/pets usually means moving subjects.
That requires a shutter speed fast enough to freeze the subject, usually 1/200 or higher.
Indoors = low light, thus you will need to greatly increase the ISO.
You will need to put the camera into manual mode to get the needed settings because the auto system is not setup for moving subjects.
In my living room, a shutter speed of 1/200 maxes out the ISO at 3200, and that is still a little underexposed.