I understand your frustration, but 1. she's already pregnant and 2. she's 22, so she knows everything about life. Nothing you say is going to matter because in her head, everything is figured out. When the baby comes, yes, she'll realize how wrong she was. But unfortunately, it's the only way for her to learn.
You are her family. Be there for her and don't talk about her situation with other family members, even if it's out of concern. When the baby comes, if she is still living without electricity, report her to CPS. Stay close to support her and to ensure that the baby is being taken care of properly. If you feel like it isn't, call CPS.
Medicaid doesn't go after the father - That's TANF. Once the baby is here they might, but during the pregnancy they definitely will not. Medicaid also provides rides to and from doctor visits if the patient does not have transportation. Most OBGYNs will not see pregnant women until at least 8 weeks