Yes, your Sharmrock or  oxalis house plant is actually growing from bulb like tubers below the soil and adding some fresh potting soil will help to support the stems. This plant will go dormant after flowering so it could look limp or turn yellow but don't give up. It just needs a rest or dormant period. Do not overwater. Let the soil dry out between watering just enough to keep the plant alive. When it is actively putting on new growth it may need water once a week but when it is dormant or resting watering once a month may be enough. Keep growing, Marianne Binetti