The general consensus is to wait till around 5or 6 months as nose_twitch mentioned. The bigger the breed the longeryou should wait, though. For French Lop I'd wait till 6 or 7 months.
i would seperate them now as rabbits canreproduce at 3 months of age and you dont want to take any chances. hecan also still impregnate her up to 6 weeks after his neuter.
I agree with FlopsandWills, you should go aheadand seperate them now, better safe than sorry. A pregnancy for a doethat young would be extremely hard on her. I have to add, I reallyappreciate that you are caring for your rabbits properly by doing yourresearch on this. Good job, Nelsonh.
Thanks everyone for all the feedback, I haveseparated them (even though they do "love" each other) and am planningor neutering Clyde (as in Bunnie & Clyde) when he isolder. The breeder I got him from also suggested Ihave Bunnie spayed when she is older, so that is my plan. Weare having so much fun with them and just really want acouple of nice pets.