23andMe is basically a data collection thing. When they send you the kit (for which you have paid something), they then ask you a million genetic research questions - about your family, your body, your health, etc. - before you can even go ahead.
Also, if you’re a woman, you can’t get a very clear reading on the genetic background since you’re missing part of it. If you have a brother, have him do it.
Basically, I’d say that if you want to do it, it will give you something although not very much if you’re a woman, but refuse to fill out their forms unless you really like that sort of thing.
I think perhaps you are partly confused on this.
Females, as well as males, can discover their ancient maternal lineage through DNA testing. Because a father's mitochondrial DNA (mtDNA) is destroyed at fertilization, a child inherits only the mother's mitochondrial DNA, thus preserving the maternal link to the ancient past. Due to this unique inheritance pattern, both males and females may directly contribute a DNA sample for testing the maternal lineage.
http://ldna.ancestry.com/learnMoreMaternal.aspx
A male providing his Y-chromosome sample also represents the DNA of his father, paternal grandfather, and so on up the paternal line. Y-chromosome results are generally identical throughout the paternal line. But because mutations do occur, it is possible for a son's results to be slightly different from his father's or his brother's.
Women, in spite of not carrying a Y-chromosome, can still trace their paternal lineage. Using a DNA sample provided by a brother, father, or another paternal relative (for example, a male cousin) a woman can treat these Y results as if they were her own.
http://ldna.ancestry.com/learnMorePaternal.aspx
So basically a woman can trace her material ancestry through her own DNA sample without having to also submit the DNA of a male sibling or paternal relative but if she wants to trace her paternal lineage she would have to use the DNA sample provided by a full brother, her father, or another paternal relative (for example, a male cousin).
So if I do decide to get a 23andMe test, I’d probably offer and pay for my brother to get one too in order to get a more complete picture.