Thank you so much guys on all your answers.
Yes, she's breastfeeding, and, yes, you are right, she must do this slowly.
I found this book to be of a great help - [edited to remove name]. You can find it on Amazon.
She's thrilled with it, as am I because I no longer have to worry my wife is going to go on some crash diet that's going to be bad for her health.
And best of all, they're running a free promo campaign right now, so you can get this book from Amazon for free over the next few days.
Wish you all the best&keep safe!