To me it doesn't make sense at all. When Howard first met Bernadette she was really kind, and in a sense, cute. Though in this Episode 13 of Season 5 was a let down. Bernadette has suddenly married Howard not mentioning any hatred for children, and has actually turned out a lot like Howard (not understanding peoples feelings), for example how she says she will work and Howard will stay home because of HER hatred towards children. Bernadette's character has changed dramatically, with hardly any factors proving that it is a reliable change in character.
I think it was one of my biggest let downs so far in the TV series. I actually made an account on here just to share my opinion about this.