Might not be a popular opinion but never mind.
I think Sue is reliant on Noel because she's lazy.
Shes always chilling with a nice cup of coffee. She has no job, although she has had pockets of opportunity to work. She does very little around the house and now there are no kids at home during the day, it's more noticeable just how lazy she is. Maybe Noel is snappy because he's tired. On a kids and counting, it showed him up at 5am to go to work, then home at 7am to get the kids to school. In that clip, Sue was sat in her dressing gown drinking a coffee, when asked why the kids weren't up, she told him she was waiting for him to get them up. Noel got kids up, fed them breakfast then made packed lunches. Why couldn't Sue do that? Why couldn't Noel go home at 8am and literally put kids in car and go? Why does Noel have to come home from work and cook dinner? Why can't Sue prep it during the day and cook it in the evening? Why is it always shown that Sue laughs at the kids whilst Noel does all the discipline? I just think Sue is bone idle I'm afraid. I think she has never had a job because she's never wanted one. Look at the pie shop. Always behind with orders yet she never offers to help out. You never see her packing orders, answering the phone or helping in any way. Every single child is now out of the house for a minimum of 4 hours per day. Sue could do something but chooses to do nothing.