I have only ever heard of babies being affected by strep b after birth. I would have thought as soon as your daughter goes into labour they will start her with a course of antibiotics and then monitor her baby closely after. Of course the older the baby gets the less likely the chance the of developing problems from the infection. I think the one month - 6 weeks stage is when its deemed there isn't a further threat.
I know 2 women who have known they have strep before going into labour and both babies were very healthy. Of course the reality is that more than a third of women I know who have had babies have probably had this and were just unaware.
I found this.... you might be able to find a proper support group from the links, I didnt try.
http://www.gbss.org.uk/
Out of 88,000 babies born to mothers with strep only 700 develop GBS apparently.