Pros
One of Booz Allen Hamilton's core values is work life balance. They do an amazing job of upholding this. Your hours will be very reasonable and taking time off is not an issue. There are also many programs for mothers including maternity leave and free care. Booz Allen also has many of the nicest people I have ever met. I have never worked with a more amicable bunch. It is amazing to be an a company where no one yells at each other and everyone gets along pretty well. Booz Allen also has quite a bit of training opportunities and will sponsor you for any number of professional certifications.
Cons
Booz Allen Hamilton is not what it once was. With the commercial side spun off, most project are government staff augmentation than anything else. For those not clear what that means, you're doing the government's job for them and not really consulting on anything. This could be anything from typing memos or doing blackberry support. If you decide to work here you should certainly network very hard to get on good projects otherwise you might be stuff on some lifer projects you can't escape. Also, pay is significantly lower than in similar types of companies. If you're young and aggressive I would try somewhere else.