Wolf:
The internet is a wonderful resource, and as you have noted, Google is your friend. The specific mishna brura discussed here can be located in pdf form at this address http://www.hebrewbooks.org/14164 (and I’m sure at many others as well). As a result of the wonderful tool known as the internet you never again need to say that you do not have a MB handy.
As you have correctly concluded, the Chofetz Chaim is saying that it is a genai for a woman to be m’vareich al hakos. He leaves ambiguous exactly what is genai about it.