The ladies are doing a tremendous job of helping you!
I'm not quite understanding from your post how much of Bigger Hearts you have done so far? If you are able to clarify that, then we'll understand better how much of a trial run of doing Bigger your little sweetie has had before declaring she didn't like the history readings. This will definitely make a difference in the advice we give you. I'm also wanting to be sure that your 7 year old is able to handle all of the rest of the skills within Bigger, as it is very possible that she just doesn't fit in Bigger Hearts overall.
It takes a very strong academic 7 year old who has had experience in listening to living books, and also is a good reader/writer/narrator/etc. to flourish in Bigger Hearts. Otherwise, we wouldn't typically advise a 7 year old to begin HOD with Bigger.
One thing to understand about living books is that they are not typically picture books, but rather are books where the author's words paint the pictures in a child's mind. They live in the mind because they are told in narrative or story form, and often include a very rich, higher level of vocabulary (which makes a living book truly live)! Many living books can be an acquired taste, especially as children who are used to a picture book style education move into this new type of reading.
I'll include a description as to why we chose the Eggleston books below, and also include an explanation of why they fit well into the "living book" category.
Eggleston's books qualify as living books in that they are written in short chapters, told in narrative form, include interesting anectdotes and stories about real people, are written by one author who was passionate about his subject matter (and consequently was a Methodist minister and later a journalist who actually interviewed family members to get the stories he wrote). They also lend themselves well to being narrated.
We found Eggleston's writing to be more memorable than any other American history text out there, yet it gives a great overview of the important men and women that our children should know from American history. Also, a biographical approach is much more personal than a study of events. I was fascinated with the reading and learned many things I had never heard before.
That being said, Eggleston is an acquired taste, whose style grows on you the more you read. His books are also not filled with beautiful pictures, so they require a more seasoned listener to appreciate the retellings. My boys loved the books and learned so much from them. It was a tough decision to choose spine books for American history, yet surprisingly most texts we reviewed were easily set aside for one reason or another until we settled on Eggleston.
The upped level of maturity in the readings within Bigger Hearts do much to prepare a child for the level of readings and work to come within in Preparing Hearts and CTC. So, if you stop the Eggleston readings, and choose a different route, it is likely that should you desire to come back to HOD later, you will have more work as a parent to make sure your kiddos are ready for our upper guides (unless your kiddos have become accustomed to more difficult readings through another route). It is better to be sure a child is well-placed, as then the readings will fit the child's skill level much better. With that in mind, I would say from what you've shared so far that your 7 year old would fit better in either LHFHG or Beyond, as it is likely that she is still needing a gradual transition away from picture books and into more living books in shorter bite-sized increments. It does sound like Bigger will be a good fit for your older student.
I'd encourage you to take another look at the placement chart and see where each of your kiddos fit as individuals, especially on the first page of the chart. Try to set aside any thoughts of combining for now, and just think where each child places on his/her own. Then, if you get a chance to pop back and share a bit more about each of your children, we can discuss possible placement options.
Blessings,
Carrie