Military divorce in MD?

My son is in the USMC. He and his wife were married in MD in Oct. 2009. In June 2010 he deployed to Afghanistan. In August 2010 their daughter was born. In September 2010 she moved with their daughter from MD to Michigan without telling him (this is only one of the major issues he has). Last week my son returned from Afghanistan and is seeking a divorce. He is 22 and she is 21. She feels she is entitled to alimony or spousal support. He would like to have at least partial custody of his daughter. Advice?