Well, no point in worrying about something you can't change anyway, and I've rarely heard of any problems for the doe due to surprise litters after the sex change fairy paid a visit. It's not considered the best age for good results and the does constitution, but it's not like they tend to fail too frequently or that it would do long term harm.
Sometimes her instincts are somewhat confused and she doesn't do everything in the right order, but that can happen with any first timer.
Just make sure they have no stress, enough food, and enough nesting material when the time comes - if they are pregnant at all, which I do not think is more likely than not considering that mine 7-8lbs. rabbits mature at about 14-16 weeks.