Character Analysis
Like Jason, Daniela is defined by a branching path in her life. In the primary universe, Daniela abandons her dream to become a famous artist after getting pregnant with Charlie. In the second universe, however, Jason's focus on building his career rather than building a family leads Daniela to double down on her artistic ambitions—and win, big time.
Mama Maybe
So which life is better? It's hard to say. Daniela the mother seems quite happy with her life, even if she occasionally doubts the path she's chosen. Daniela the artist, on the other hand, seems to be genuinely content with her career. Check out how Jason frames this distinction: "My Daniela carries a weight and a distance in her eyes that scares me sometimes. This Daniela is an inch off the ground" (5.283-284).
At first, Daniela the artist seems like she's living the good life. She's putting on lauded art exhibits. She works on ambitious, experimental pieces. She has a youthful energy. So is everything in her life perfect, and is she regret-free? Not quite. Although Daniela2 is indeed grateful for her success, she harbors some regrets about how her relationship with Jason went down. She wouldn't have hooked up with Jason1 on his visit to her universe otherwise, right?
A Multidimensional Love Affair
Basically, everyone has regrets. Loving mothers regret their lost career ambitions; successful artists regret not focusing on their personal lives. We see the same dynamic in Jason's research career. The path not taken always seems extra attractive, partly because it's a mystery how it would have turned out.
Nevertheless, Daniela finds comfort in her love for Jason. This is true even when he's replaced by Jason2, who "looks at her with a smoldering intensity that reminds her of the way new lovers stare into each other's eyes" (9.23). It's a completely different relationship vibe. While this is nice at first, she misses the hard-won stability she's built with her Jason over the years—as evidenced by her decision to stay with him despite the appearance of an army of doppelgängers.
That's right: Daniela could choose any Jason out of an army of Jasons, but she still chooses to the dude she actually married.
Just think—this marriage is so strong that it survived two affairs. Those affairs happened to be with parallel-universe versions of the respective spouses, of course, but that's still worth something, right?