The results of my maternal haplogroup tested at 23andMe is T2b, a subset of T2, which comes from my mitochondrial DNA. This DNA is passed through my maternal line, so it comes from my mother, her mother, her mother, etc. all the way back.
I find it interesting that the example populations are Northern European and Spanish. My Ancestry Composition results showed 0.3% Iberian and 1.1% nonspecific Southern European.