His eldest is around 18 or so?
Could she be at university/college, moved in with friends, with her mum etc?
Kai is still much younger, only 15.
She is at an age where you expect them to not always be there. He isn't.
Also, in the gingerbread bit of her stories Andrew actually seemed to enjoy/be interested in Evie's company, was talking to her and explaining what they were doing etc. Soph was just filming everything and even talking to Aria through a camera lense.
Out of both of them he'll still be the most present, consistent parent to the baby despite his long hours.