By SARAH FITZMAURICEHappy family: Naomi Watts and Liev Schreiber took their boys Alexander and Samuel for a fun-filled day out in L.A. yesterdayIt�s very rare for a person�s work, love and family life to all be going swimmingly at the same time but for one Hollywood couple things are looking better than ever.Naomi Watts and partner Live Schreiber not only have successful actor careers and a