This is a triangulated DNA segment (courtesy of MyHeritage) that I share with a woman from Texas and her two daughters. The red is daughter 1, the yellow is daughter 2, and the orange in the middle is their mom. Interestingly, I share two 6cM DNA segments with daughter 1 that I do not share with the mom. Right now I don't know if those are coincidental or if I'm also related to daughter 1's dad.
After reviewing the mom's family tree, I determined that I am her fourth cousin once removed and a fifth cousin to her two daughters. Our shared ancestors are Joel White (c.1790-) and Rebecca Barnes (c.1795-) of Clay County, Indiana. Her great-great-grandmother was my great-great-great-grandmother's younger sister.
Now that I've figured out how we are related, I can map this portion of Chromosome 2 on my maternal side. I simply download the shared segments from MyHeritage into an Excel spreadsheet...
| Name | Match Name | Chr | Start Location | End Location | Start RSID | End RSID | cMs | SNPs |
| Lisa Perry | [~] | 2 | 172429907 | 202693975 | rs6729179 | rs55852210 | 23.7 | 13824 |
| Lisa Perry | [~] | 10 | 131054514 | 135523246 | rs35100572 | rs9665515 | 9.5 | 3455 |
...which I then copy and paste into DNA Painter. I did not include the two 6cM DNA segments that I share with daughter 1, partially because they don't meet DNA Painter's default 8cM exclusion and also because I doubt that they're from the same ancestor.
My great-great-great-grandmother was Lydia Celia White (1820-1848), the daughter of Joel White and Rebecca Barnes. At the present time, I cannot tell whether the shared DNA segment came from Joel or Rebecca, so I have assigned it to Lydia (depicted in lemon yellow below). Anyone who shares DNA with me at that location should be related to Joel White and/or Rebecca Barnes.
