She studied parenting in college, but apparently didn't practice what she learned as part of her life. She also practiced all of Supernanny's techniques unsuccessfully. She admitted to being burned out by just being a mother and wishing she had some other interests to occupy her life.
She seemed very high-strung and frazzled by being alone with three children all day. For example, during Observation, when trying to put JJ in timeout in his room, she started crying and expressing frustration and confusion ("What do I do now?"). When JJ wouldn't stop screaming, she just gave up and took him out of his room.
Danielle is notable for her highly disrespectful behavior to Jo. She and Jo did not agree on skipping JJ's nap when they found, after 45 minutes of the scheduled 1-hour naptime, JJ had stayed awake the whole time. Jo said Danielle should now let JJ finish out the 15 minutes in his room, while Danielle insisted JJ still take a nap. Jo disagreed, because this would throw the entire family routine off schedule. In response, Danielle rolled her eyes at Jo, interrupted her, barked at her in a rude tone, and told Jo that it was her fault if JJ misbehaved that day (because of having the disagreement in and just outside of JJ's bedroom so that he couldn't fall asleep, and insisting that JJ not get a nap, which would make JJ cranky).
She was 30 years old at the time and is now 37 in 2017.