Good luck on your girls. I just want to mention that once your rabbits start to get their hormones (12 weeks) it's possible that they will no longer get along, and will not be able to be kept in the same cage anymore. This comes from the heart. It happened to me. Female rabbits have a high risk of getting uterine cancer (80% get it by the age of 2 years if not spayed), so it is very important that your girls be spayed for their best chance at a long healthy life. Once your rabbits are spayed and then healed up (4-6 weeks) then you can slowly begin to re-bond them. Re-bonding is the process of making your rabbits friends. Female rabbits especially tend to be very territorial. The best combination for a successful couple is male-female. Female-female and male-male combinations are difficult at best, and some never work out. So you will have to face the possibility that your girls may never become friends, and it may be necessary to keep them housed seperately. Just some words of caution.
Best of luck!