Hi, I'd like to help you with your question.
It sounds like you have done what you can to help. You have not allowed them to take advantage of you. You also have provided the help they needed to get on their feet, which they did not take advantage of. Most people would have used the time living with someone else to find a job and become self sufficient. This shows you that no matter how much you would help, they would only use you and not improve their situation. Until they decide to be responsible, they will not change.
You can continue to be supportive but changing someone else's behavior is not possible. That does not mean it is easy to stand by and watch your daughter and granddaughter in this situation. What you can do is learn more about co dependent (enabling) behavior so you know how to respond and when to help.
Co dependent behavior is usually learned behavior. The person feels responsible for the behavior and problems of their partner or relative. They feel guilt, low self worth and a need to feel loved. They will get this love in any way possible, even if it means getting hurt themselves by being in a dysfunctional relationship. Their fear is being left alone and not having anyone, which keeps them in the bad relationship.
Here are some links to help you:
Setting Boundaries with Your Adult Children: Six Steps to Hope and Healing for Struggling Parents by Allison Bottke
Facing Codependence: What It Is, Where It Comes from, How It Sabotages Our Lives by Pia Mellody, Andrea Wells Miller and J. XXXXX XXXXX
Love Is a Choice: The Definitive Book on Letting Go of Unhealthy Relationships by Dr. Robert Hemfelt, Dr. Frank Minirth and Paul Meier M.D.
You can find these books on Amazon.com or your local library may have them for you.
I hope this has helped,