To some of you who might be new or relatively new to this whole "portrait" thing, let me give you a little history over the last, say 30 years. Portraiture was and probably still is connotatively defined as a "sitting" where you places the subject in front of a background ( real or painted) and light the subject with light ( real or artificial) and work your magic to attempt to get a revealing likeness of them, their personality, on film.
It was essentially, a copy of Rembrandt lighting and posing, with new materials. The reason this was, and is done, in this manner is to pose and light this person, to get them into a flattering position, with flattering lighting and then to get a flattering expression. Worked then, works now.
With the glut of magazines in the 70s and onwards a lot of commercial product photographers started shooting "lifestyle portraits". These were usually families or kids or lovers engaging in fun activities, and then capturing this on film. The public and as well, established studios liked this style and many people started doing it. In fact wedding photographers were some of the first, who started doing a more "candid" style of wedding coverage and it caught on.
In the last dozen years, a lot of women have essentially taken over this style for childrens photography. I saw Joyce Wilson in 1987 in a seminar at Winona School of Professional Photography have children playing, and yes even jumping up and down on a bed while she captured their glee. Nancy Brown a commercial photographer changed her product and clothing business to stock photography, of families , children and lovers to set up and do this same type of work.
The bottom line is there is nothing new about this "lifestyle" style of photography and it has all been done before. So no, you are not copying when you are doing it.
This may be a lot of people's first exposure to it, here with Cheryl's great work. Cheryl is new to this profession and has not "invented" anything. She is, and is going to be a great photographer and will reach the top of her game. In fact her knack for self promotion ( believe me, that is a good thing) is amazing at this early stage in her career, and her "eye" is exceptional.
But please, if you think you are copying anybody's work, just keep it up and you'll eventually find your own nitch and your own calling. There is almost nothing that is new. It's all been done before, in slightly different ways.