Yes, she'll be ok on her own - unspayed females really do not need or want companions, since they're hormonally thinking about protecting litters most of the time (even if they've never had a litter). They typically don't do well with companions in the same cage.
And as a warning, the two babies you are currently housing together will most likely need to be separated once they reach puberty. Baby bunnies love to have company, but once they reach 4 or 5 months they will probably start to fight when their hormones kick in. Then it will be safest to separate them so that they don't injure each other. Also, make very very sure that they are both females or you could have a potential pregnancy.