Are you asking in terms of legal or practical requirements in terms of getting a job, or my own personal opinion? I’d say that what’s needed is a solid grasp of the subject matter, an ability to express that subject matter in an understandable way and to change that approach if it isn’t working, and ability to read students as to how well they’re coping, and an ability to treat students objectively.
None of those things are, unfortunetly, supplied simply by caring for a child. That care may well be a motivation to become qualified in those areas; on the other hand, they may well be an impediment to aquiring them. And some people may simply be unable to be good teachers.