It’s probably been mentioned already, but I can’t help but feel that Louise is so scarred from her own childhood that she worried Darcy’s would mirror hers. I mean that in the sense that because her mother died and her father was left alone and remarried, Louise felt pushed out when her father and stepmother then had another child.
This wasn’t helped by her stepmother sounding like a really nasty piece of work. I think she worried that Darcy would feel like she was being pushed out when Louise met Liam and had Pearl and felt like she had to overcompensate.
However, instead what’s happening is that she’s smothering Darcy in love to the point that the child feels like she can’t do anything her mother doesn’t want or like. She is, as any child would, enjoying all the attention and affection her mother gives her and worries that if she doesn’t carry on exactly as she always has, that will change. Children are perceptive, she probably realises that Louise is trying to heal her own inner child by trying to treat Darcy the way she wished she had been treated. Darcy is completed trapped in a cycle of doing what Louise wants to keep Louise happy. Louise needs to sort out her own issues on her own and not use her children as a way of fixing her own trauma. They are separate entities to you, Louise.