my sister went missing

3 months ago my sister messaged me asking if she can stay with me for a few days i was in another state so I told her not this week etc. She then told me she ran away and its cold outside mind you were all the way in conneticut so it was snowing around that time. She ran away from foster care because they finally found a home for her but far away. I was so worried. She went to her friends house deleted facebook and didnt tell me the exact place she was. 2 weeks later I messaged her no response almost everyday until march 28 we talked and again yesterday she still hasnt returned home police are searching for her and i feel like a cover up. they showed her picture on the news again yesterday saying she was possibky kidnapped her foster family is desperate to find her. She told me shes now at her cousins in another town what should i do guys