I've lived in North Dakota for all my life and remember the murder case that was referenced above. I vaguely remember that the 8-year-old was named Jody and she had blonde hair. I may be confusing two different cases because there were two families killed a few years apart in the Grand Forks area by fathers/husbands/boyfriends. Both cases would have been covered extensively by the Grand Forks Herald. I was a kid and found the cases really unsettling, enough that I still remember them.
I've read your posts with interest and some of what you've written sounds familiar. I'm not familiar with a lot of the words your grandson has come up with or any recent murder suicides that exactly match the details he's recounted. I don't believe there's a Kalevala in North Dakota or any formal Kalevala festival, though it's definitely a Finnish word. "Cupboard," however, is the word that everyone uses for the kitchen cabinet and the cupboard under the kitchen sink, the bathroom closet, etc. I would expect a North Dakota child to call any of those things a "cupboard." North Dakota is extremely rural and it would be normal for a woman living in the country or a small rural town to have a garden with vegetables and flowers and for her child to spend a lot of time with her in it, probably barefoot! Pressing leaves is an activity I did with my mom in the 1970s. It's the sort of thing that people might do at any time.
There are hills in various parts of North Dakota, including the Turtle Mountains (actually rolling hills that look a lot like a turtle's back) and in the area around Des Lacs, North Dakota. There are also the Badlands near Dickinson and Medora in eastern N.D. that look more like mountains to us. It does snow a lot here and get very cold, as in 20 to 30 below zero on some days, and kids do like to go sledding and have to wear warm clothing.
For whatever this is worth there are a couple of Finnish-American settlements near American Indian reservations in North Dakota and the two groups have intermarried pretty extensively. My own grandfather was Finnish-American and he spoke no English until he went to school.
The town I grew up in was Rolla, North Dakota, near the Turtle Mountain Indian Reservation in Belcourt, North Dakota. Unfortunately, domestic violence and child abuse are quite common on the reservation there for many reasons. There are also a lot of Finnish surnames in the Stanley, North Dakota area which is closer to the Fort Berthold Indian Reservation which has Mandan, Hidatsa and Arikara Indians. Of course American Indians and their families live in towns all over the state and in surrounding states. They'd probably have relatives in Montana, Minnesota, South Dakota or even Michigan, where there are also a lot of Finnish-Americans. The climate is similar in all of those states. I think you said he mentioned a "mine" in one of your posts. North Dakota does have coal mines, but they're above ground. Lignite is one of the most famous areas in the state for coal mining. There was also some mining done in the hills around Minot in the early to mid twentieth century.
Some of the older Finns in the state still speak what is now an archaic version of Finnish, according to my cousin who recently went to Finland as an exchange student and learned modern Finnish. The people on the Turtle Mountain reservation have a sort of dialect/speech intonation that is heavily influenced by French and Cree/Ojibwa. Dancing at pow wows is also pretty popular with Indians on both the Turtle Mountain and Fort Berthold reservations. Kids as young as 2 are dressed up in really bright costumes with feathers and beads and they dance in competitions for prize money. They have categories for tiny tots, children, teens, adult men and women. Some of the dances are jingle dress, fancy, etc. It's a really festive occasion the kids look forward to. There is drum music and the typical Indian language songs. Your previous post made me wonder a bit if he might have been talking about a dance at a pow wow. I have no idea if any of the words he's used are American Indian in origin but it might be an interesting thing to check out. They have annual pow wows on the reservations, at college graduation ceremonies and people travel to other states and provinces to compete.
If you believe what he's saying might have some basis in a past life, I'd say it's as plausible as anything else that a Finnish-American woman could have had an abusive Indian boyfriend or husband and there was an incident of domestic violence or murder of her and her children. Some of what he's recounting sounds a lot like a mix of the two cultures to me. It also sounds like he could have mixed up different possible past lives or things he saw or heard on TV or from people in his life. Any kid is going to be pretty confused and mix up fantasy and reality and dreams.
I have zero past life memories and am something of a skeptic, even though I'm very interested in the topic and in history. If past lives do exist, I doubt if we're intended to remember them too clearly. It's hard enough living in the present. All this is interesting, if disturbing, but if Kade were my child I think I'd want him to forget this as quickly as possible, though I'd certainly let him talk about it and listen in a nonjudgmental manner. I'd definitely find out what is going on in his present life that might be bringing up the images of violence.