Also, I believe someone mentioned that they think welfare checks in the US involve placing the person in handcuffs, which could traumatize the girls.
I just want to add that police don't cuff you during a welfare check, especially not in a situation where the person is already anxious or unhinged. It would be unnecessary, unless, of course, the person is behaving in a threatening manner and needs to be restrained somehow. Welfare checks are meant to be compassionate, careful visitations to the person's place of residence; arresting the person would negate that and also communicate a message that people who potentially need help should be criminalized.
The only trauma I would imagine the children experiencing is if Alice didn't answer the door. Police cannot leave the residence until the person has made contact with them. If she doesn't open the door then they'll break it down. THAT could be traumatic to the girls but, honestly? I can think of roughly 10,000 more traumatic things happening in that home, and if checking in on Alice, who is obviously off the rails at this point, means they can get her some help, even if they have to possibly be aggressive getting access to her...so be it.