Amanda Prowse’s My Husband’s Wife begins with Rosie Tipcott happy with her life in the town of Woolacombe. She and her husband Phil have two lively young daughters, her in-laws love her, and she has a best friend to confide in.

Sure, there are things she’d change if she could. Her mother walked out when Rosie was a baby, leaving her to be brought up by an overwhelmed and emotionally withdrawn father, and while Rosie would like another child, Phil points out that they can barely afford the ones they already have. A builder who works for his father, Phil has managed to get a new job renovating a fabulously wealthy woman’s mansion, but Rosie’s work (cleaning caravans) is only seasonal. Plus, they only have sex once or twice a month, thanks to the kids and their work. Still, while money might be short, love isn’t.

Or so Rosie thinks. One day she makes a dutiful visit to her father, only to be told that her mother has died. Rosie sometimes had imaginary conversations with her mother, so she’s hit hard by the realization that these talks can never be real. She goes home, where Phil has news too. He’s met someone else and is moving out.

When it rains, it pours, and in this book, the storm never lets up. The other woman, Geraldine, turns out to be the mansion’s owner, and she offers Phil a life that Rosie can’t match. What really devastates Rosie, though, is when Phil insists on the girls spending time with him and Geraldine, who immediately dazzles them with Ugg boots and an adorable puppy.

Rosie is determined to be a good mother, not the sort of person who walks away. But she’s steadily edged out of her daughters’ lives. Phil talks about joint custody and suggests the girls be enrolled in a posh London school, because with Geraldine’s business in the city, it makes sense for the girls to be there, too. Plus, what an educational opportunity for them. Rosie’s in-laws try not to take sides, but when Geraldine announces she’s pregnant, they’re thrilled. Even Rosie’s best friend starts to think Geraldine is a good person, so when Geraldine gloats to Rosie that she’ll take everything Rosie ever loved or wanted, no one believes Rosie’s claims about this.

This was all fascinating, and I couldn’t wait to see how Rosie would dig her way out of such a deep hole – especially as things get even worse for her, in a way that I won’t spoil. Rosie struggles on as best she can, trying to be a loving and responsible mother to her girls, and reconnecting with her father. I liked this too, because her father turns out to have a good and solid heart under his reserved exterior. He’s the only relative in the story whose relationship with her gets better throughout rather than deteriorating.

But that’s not enough to make up for the book’s ending. When a heroine loses everything, you want to watch her recover. You were there with her during her downfall, so you want to enjoy her upward climb. Here, as the number of chapters left kept shrinking, I wondered how the author would fit Rosie’s rebuilding of her life into what remained of the book. And the answer is that it’s all crammed into the last few pages in a rushed, unrealistic conclusion. Rosie suddenly has a new man, a home business that brings in a “small fortune”, and even a “flat, tanned tum”. I felt no chemistry between her and the man, and I really disliked the hasty resolution of the Geraldine affair.

The idea behind the book is great – a woman who wants most of all to be a wife and a mother is abandoned by her husband and struggles to keep her children safe. In doing so she has to re-evaluate everything, and figure out who she is other than a wife and a mother. And for most of the story I was caught up in it. Woolacombe has an authentic small-town feel, Rosie’s girls are real kids rather than plot moppets, and I liked Rosie herself a lot. This was one book I really hoped would stick the landing, but the ending means that My Husband’s Wife gets only a qualified recommendation.