Welcome to BB MaloneBunnies!
They all should be separated until they are spayed/neutered + 4-6 weeks for hormones to dissipate/level out. After that you can start the bonding process in a neutral area to all of them. BB has a great bonding article here that outlines the basic process really well:
https://binkybunny.com/BUNNYINFO/tabid/53/CategoryID/9/PID/940/Default.aspx
Some other things to keep in mind is that rabbits can breed through cages and males are still fertile for 4 weeks after their neuter. It’s very important that different genders be kept separately. A single female can give birth to very large litter and be re-impregnanted as soon as they give bith. Your 3 bunnies could become 9-15 bunnies fairly easily (it takes literally one second for them to breed) so I can’t stress gender interaction caution enough. Males can be neutered as soon as their testicles descend (usually at 3-4 months) and females can be spayed as early as a vet is comfortable, sometimes as early as 4 months, but usually waiting until 6 months is recommended. Estrogen helps with bone growth and development.
Once everyone is desexed bonding will be a lot safer and more feasible. This forum is GREAT for bonding support (I have 5 rabbits all bonded to each other) so I would definitely suggest creating a thread when you’re ready to bond them so people can give you advice or support as you go. I’m glad that one of you is keeping the first bunny full time. Going back and forth would be very stressful for a bunny as they thrive on routine.
I’m glad you found your way to us! Please keep us posted.