You can cut the baby raspberry plant away from the mother by snipping the branch once you have grown new roots. Cut as close as you can to the young plant and keep the detached raspberry start protected for a few weeks as it grows new roots. To test for roots give any cutting a good tug. A firm grip into the soil means new roots are down there and it is time to move the potted cutting to greener and larger pastures. I suggest you wait until fall when the weather is cooler and then dig up and plant your new rose cutting. Keep growing, Marianne and Joe