Suggest Treatment For Extreme Back And Leg Pain During Pregnancy

My daughter is 6 mos pregnant and has had 3 episodes of intense back and leg cramping in the last 10 days.. She is debilitated for multiple hours and has experienced vomitting as part of this picture. She was seen in the ER today and kidney involvement was ruled out. All that was prescribed was tylenol and heating pad. Apparently the dx is "muscular" at this point. Is there more we should do for diagnostic purposes and what else might help the pain?? She is extremely uncomfortable. Thank You