I am pretty sure I only think this because of reading mumsnet relationships.
Anyone read the Cormoran Strike series by Robert gabraith (aka j k Rowling)?
I may be wrong but I am fairly convinced she is playing out the 'slow boil' of an abusive relationship with Robin and Matthew. And how a capable, reasonable woman can get sucked in. Anyone who has read the series think his abuse is going to escalate to physical violence soon (maybe once she gets pregnant?!). There are red flags all over the place!!
Although I may be reading WAY to much into it.