I just think she struggles with being a mum. She did it, she had one child, it hasn't been great and she's over it. Before the baby, she used to be a fence sitter. Now she wants to go back to being herself, albeit slimmer and grungier self. She even sold her baby clothes a few months after Ralph being born. Something really tells me she regrets all of it, hence, the constant need to go away without the kid and to appear a single female in her insta pics.
It would be an interesting topic to speak about but Anna isn't the one to speak about difficult stuff. I am sure there are a lot of women who feel the same.