The best thing to have done would have been to separate her from all male rabbits when she was 8 to 10 weeks old, and not bred her before she was at least 6 months old. Since that isn't what happened, the next best thing is to get her away from them now. If you have a male, put him in a separate cage.
One of the main reasons rabbit breeders keep the sexes separate, is because the rabbit has a weird reproductive system. The uterus is v-shaped, and it is possible for a doe to get pregnant on one side only, and start another litter on the other side at some later date if a buck has access to her. Most does refuse the buck when they are pregnant, but it can happen.
So yes, it is possible that your doe might be carrying a second litter that are due some time soon. If she is still living with a buck, she is almost certainly pregnant with a litter that are due about 31 days after that first baby was born. This is another reason why breeders don't keep bucks and does together - does will rebreed immediately after kindling, and cranking out a litter of kits once a month goes really hard on the doe.