Lots of problems for me.
I am reading the series in order, but I'm now thinking that won't help in keeping characters and story lines straight. I know Gareth Alexander has his own book, #6, but here he is already happily married. So these books interweave, which will be annoying.
There are two kids in the book which aren't well-defined characters, but take up a big chunk of the story. They didn't bother me as kids in romance often do because they had a purpose other than to be adorable props, so that was better than expected, but still, not as good as it could have been.
I tagged "disability", but Alice's physical problems are not well handled, in several ways. For one -- and this runs through the whole book -- her treatment by others feels anachronistic. She is a governess, but she is always accommodated. As if. Also, while her panic attacks are handled well by Ethan who apparently has personal experience with them, when it comes to her bad hip, he is autocratic and heavy-handed, and it's only through authorial fiat that the "treatment" actually helps. The autocratic behaviour also comes to the fore when he offers her wine for dinner, she says wine doesn't agree with her, and so he hands her...wine. Later he wonders why she didn't just ask a servant for water -- why didn't he do that?
A lot of things feel anachronistic. Like, apparently George, one of Nick's brothers, is gay. Nobody but Alice raises an eyebrow, and even hers just go up for a second. Especially Ethan ought to have more of an issue with that (because of his deep, dark secret). But nah, they're just gonna make George their agent in mainland Europe, because people are taking notice of his affections; no biggie. No discussion, no nothing. And this is the same book in which the villain rapes anyone at all, indiscriminately, but with particular attention for young boys. So we get a pedophile rapist and a gay non-entity. I'm sorry, that's not good enough. I don't ask (well, I don't ask very loudly) that mainstream romance feature full-blown gay couples, but an occasional good relationship even during a time when it was illegal and deadly would not go amiss -- they did exist in reality. Or at least have a decent discussion where somebody speaks up for the gay guy when the "unnatural deviant" argument gets trotted out. Which also happened at the time. And I think that's especially necessary when you have a one-dimensional villain who is a pedophile; the quintessential bogeyman anti-gay conservatives still trot out to this day.
The way Alice takes to sex, especially considering her background, seems very modern. I mean, it's nice for a heroine not to shy away from a penis, but she's very enthusiastic.
Ethan charts a menstrual calendar. He was almost a hundred years ahead of his time; nobody actually understood the menstrual cycle in the Regency. Since many mammals have a bloody discharge during estrus, it was assumed that menstruation was the most fertile time for women, which is alas very wrong. It took until the early 20th century before people actually figured it out. He did mention sheaths, which did exist, but he didn't bother using them.
Beyond anachronisms, some things just don't make sense. Ethan has lived like a recluse and didn't socialize for years, but at some point his neighbours suddenly take a very active interest in him, too active and helpful an interest, really. They're apparently also all acquainted with Nick -- and yet, Nick never even heard a whisper that Ethan was married and had two kids? That's totally unbelievable; people gossiped like mad, and Ethan's situation was particularly juicy.
Also, what's with the names? Alice is really Alex/Alexandra (she lives under an assumed name because of the deep, dark secret). She tells Ethan that at some point. Now it would make sense that he'd call her Alice in front of others, and Alex or Alexandra when they're all lovely-dovey but he's all over the place with it instead.
And then we have stuff that I wish weren't in the book at all:
The situation between Ethan, his ex-mistress/wife, and Nick is OTT. The book didn't need that extra complication. The entire ending feels OTT as well, super dramatic, real time villainry -- meh.. And lastly, to me it didn't feel real that Alice would react like she did to Ethan finding out her deep, dark secret. She felt like she had agency, and it made no sense that she would have just thrown in the towel. I mean, by all means, have doubts and worry about it, but don't just give up.
That all said, I can see the bones of the story underneath the problems, and the bones aren't bad. I like both main characters, Ethan is a better man than his occasional autocratic behaviours seem to indicate (I actually think that's an authorial mistake; his character isn't consistent), and Alice is pleasant, smart, and a good fit for Ethan's broken family.