Looks like she won't get 'generous' rises in future:
http://www.nursingtimes.net/whats-new-in-nursing/news-topics/nurse-pay/nurse-pay-rises-to-drop-below-1-warns-nhs-chief/5010705.article
I didn't think midwives were that well paid in comparison to other graduates. Of course I don't know what level your wife is at - maybe she's a manager?
I do know that my daughter, who is an IT Project Manager for an NGO (not the best payers in the world) has decided that, much as she'd love to, she just can't afford to re-train as a midwife because the salary she could expect would be so low - about £21K I think. Checking on the pay scales, I see that even a midwife manager only starts at £30K.
If that's true, I certainly don't begrudge your wife her pay rise