Andnow we have both parents.
Our Life 2: Mrs. Nichole Baumann (Step 2)
As Tamarack would say, though maybe not about this subject, wow! It's the other Mrs. Baumann, Tamarack's very own mother. She also exists and you will get to see her around eventually, just not in Step 1.
Now, while the grandparent Baumanns are clear opposites, the younger Baummans are a power couple of two extremely similar people. They're a pair of self-sufficient, highly educated individuals who value learning like the air they breathe. By Step 2 Nichole is not only a PhD holder like her husband, but she has two Masters Degrees to her name. Frederick only has one of those. That kind of drive is why they're together.
During her many years of pursuing degrees, Nichole believed she would never be in a relationship past the frivolous ones she had in high school. It was fine. She would be too inconvenient of a spouse who was too focused on herself. Who would put up with that? And if she had to stop doing what she was doing, she'd rather be single. Nichole glibly explained as much to a fellow student who she worked and studied with often. Naturally, it was Frederick. He used that opportunity to mention himself as a possible candidate for a man who wouldn't be bothered by any of that, and in fact appreciated her dedication to preserving and improving her own life and also thought she was pretty, so... They've been partners ever since.
Nichole married into the Baumann family. She isn't directly related to Dorothea and Ernst, and she doesn't have the best relationship with her in-laws. Dorothea, in fact, despises her. Ernst tries to be neutral on that matter, but it often feels like defaulting to his own wife's side because he won't defend Nichole much from Dorothea. Those two love their son, naturally, so Nichole is the easier target to blame whenever there's strife. There is often strife. Frederick doesn't care about having a relationship with his parents and Nichole doesn't care that he doesn't care. However, Frederick loves his wife, she was his choice. The dynamic frustrates Dorothea to high heavens. It's only gotten worse when the situation with Tamarack required Omi and Opa to become her (supposedly) temporary guardians.
While Nichole can certainly be blamed for not being there for her own daughter all these years, she isn't an evil presence who has taken a father and son away from his family, as Dorothea likes to imagine she is. If Nichole and Frederick were more open to listening to people not as "smart" as them, and if granny Baumann could stand to hold her baby boy more fairly accountable when bringing up criticism, perhaps they could've come to better compromises over the year and avoided some issues entirely.
As for why she allowed her unpleasant in-laws to take in Tamarack, Nichole feels like she has something to prove. To the world and to herself. Life would be a disappointment, and she would be one as well, if she could never reach her ultimate goal of having a PhD. She couldn't let that go, and was with someone who had the same kind of ideals. Nichole and her husband both strived for the same time-consuming thing and were unable to be there for Tamarack. Of course, her commitment to being a worthwhile researcher is what made her become such a disappointing parent. But in her mind, Nichole is doing what must be done with the time she has. It's not because she doesn't care for Tamarack at all. There was just no other option. Nichole isn't able to say it often because she doesn't know how to make it happen, but she hopes they'll be able to have a close mother-daughter relationship at some point.