Good evening, I would like to assist you today.
You are absolutely correct that each child advances and matures at his or her own pace. Many factors help to determine when a child is ready to take on certain tasks; the upbringing of that child, personality, genetics can play a part, and of course the environment and people that influence the child on a daily basis. Just like with schooling, however, there are general ages when children can be expected to be mature enough to handle certain tasks. As you mentioned, your 7 year old can make waffles on her own, some 1o year olds can't do that, but generally that is because they are not taught to, and given the opportunity
I think that overall it truly is dependent on the personality of the child and parent, as well as the other factors that I mentioned that determines when children are ready for certain responsibilities. It takes a parent knowing his or her child, and exposing the child to different tasks, supervising and giving them a chance to do it themselves. Of course age appropriately; no matter how mature a 8 year old may seem, I would not suggest letting them light the fireplace.
There are various resources however that do provide insight on when children may be prepared for various responsibilities; please give me one moment, and I will retrieve several for you
Above are three pretty comprehensive lists by age, some even start with infants, of when children may be expected to handle certain chores and responsibilities
I would lastly like to add the importance of being patient with the children. I am not aware of all the specifics of how your step children were raised, but I do know that it has to be tough, at least mentally to not have one of your parents in your life, especially it being their mother. Definitely set rules and boundaries for the children, because following rules and knowing boundaries can mean the difference between life or death, however understanding their background, and what they must deal with mentally in regards XXXXX XXXXX mother, do be sensitive and understanding in your approach with them. If you have any further questions, or feel that I have not provided you a sufficient answer, please message for earthsister. Thank you