Hello and welcome to RU.
I do hope that your doe will be ok. She may have more kits to be born, or there could be a problem. Please give her a warm safe quiet place with bedding for her to make a nest and keep a close but discreet eye on her. If she is in any way distressed I would want her to see a vet asap.
As advised by another poster, if the buck was present when she gave birth she may well be pregnant again, note the date on your calendar, if so she will give birth again in approx 31 days time.
I don't want to sound too negative but I totally agree with the other posters, there are far too many rabbits in rescue (many of whom incidently started out as much loved new members of the family aquired from a friend who "hobby breeds") to breed more. Also, unless you know your rabbits parentage for 3 generations then you could well be breeding rabbits with inherant health problems/deformaties.
It would be possible for you to get your buck neutered right away and the doe when she has weaned any kits she might have later today. The male needs to be kept away from the female for about 6 weeks post operatively as he could still be fertile. The female would need a few weeks to recover from her op before rebonding in a neutral place can take place.
Either way you will need seperate accommodation for your 2 rabbits for some weeks yet.
May I ask how old your rabbit is please and how long you have had these two.