More secrets and lies?

I have never been much interested in the ancestry craze that has taken hold these past few years. I know what I am: Whitey McWhiterson. I know from which part of the world my great-grandparents hailed & have always doubted that there would be some sort of genetic whammy in the mix. My hubby, on the other hand, was always keen to spit in a tube and send it off to some genetic testing company. He did it a few years ago and got me to do it as well. As I had predicted, there's no sort of 'big reveal' for either of us, genetics-wise. Although, I am, like, three percent Neanderthal and that was pretty trippy to find out. The hubs discovered some recent Eastern European ancestry that probably came about from someone having been unfaithful to someone else a couple of generations back. Still, it's not like he'd found out he was part Polynesian or African or something. 

I posted on here some months ago about the discovery of who my mother's bio dad was and how thrilled my mother was to find out specific information about the man. I, on the other hand, felt angry when reading about his life. 'Isn't he handsome?' 'I think you have his nose.' All I could muster up in response was, 'I guess so.' He'd literally lived almost the whole of the 20th century and had not been in contact, although he knew perfectly well where my mother was. I read from his obit, found online, that he was 'survived by a step-grandson'. Whatever. 

So, my mother's 3 bio-siblings were also raised in San Francisco. The two boys were kept by their mother and the two girls, my mother and her half-sister, were given up for adoption. My mother found out who her biological mother was when she was 16. She'd been a friend of the family who'd regularly come by for visits, ostensibly to get a gander at my mom while she was growing up. Finding out that the 'family friend' was actually the woman who gave my mom up didn't sit well. As a result, I never really had contact with my bio-grandma although she'd lived her whole life here in town. Some of my bio-cousins, interestingly, had even lived a few miles from my childhood home. My mother tells me that we all got together at least once way back when. I don't remember. One of those cousins now lives very near my mother out in the Central Valley. They have had the occasional lunch date and even chat on the phone. This cousin is very outgoing and very interested in her biological family. She and I email from time to time. She's very keen on finding out ancestry stuff & spends a lot of time on said sites. I received a mail from her this morning letting me know that she's found someone related to us, perhaps another half-cousin or second cousin, on the 23 & Me site. We three are all about the same percentage related to one another. As a user of the site, I am also able to see this mystery person. She and I are connected through the maternal line, sharing the same mitochondrial haplogroup. So, either my bio-grandma had given birth to a third girl and given her up for adoption or...I dunno, really. My sleuthing bio-cousin just sent this mystery relative a note. May she respond soon as my interest has been piqued!