05/30/2011 at 01:00 PM EDT
Memorial Day weekend was family time for Maria Shriver.
"Nothing could be better than going to hit up the Malibu house," her son Patrick, 17, Tweeted
Saturday. His father, and Shriver's estranged husband
, Arnold Schwarzenegger was spending time at his Sun Valley, Idaho, home, but he flew back to L.A. by the end of the weekend. On Sunday night, though, his family dined out in Malibu without him.
Shriver, 55, also found time to remember those who died in the line of duty.
"This weekend, I'm thinking of all who gave their life, and all the families who lost a loved one, in service to this great country," she Tweeted
Sunday. "You have our deepest gratitude and respect. God bless."
The mother of four turned to one of her daughters to find some fitting advice.
"My daughter once gave me a great Plato quote that said, 'Be kind for everyone you meet is fighting a hard battle,' " Shriver wrote on Twitter
Monday. "We don't know what is going on inside of most people."
She added: "On this #MemorialDay, when so many are grieving in obscurity or silence, let's keep that in mind. Be kind so many people are grieving."