Nick Cokas and Katharine McPhee
03/11/2014 AT 07:30 AM EDT
After a long separation, Katharine McPhee
and her husband Nick Cokas
are ready to give it another try.
"They're working on their marriage and spending a lot of time together," says a friend of the couple.
The pair were spotted out walking their dogs this past weekend in Los Angeles, more than nine months after they originally separated – and five months after McPhee, 29, was revealed to be involved with a married man
, director Michael Morris, who is married to actress Mary McCormack.
McPhee and Cokas had remained friendly throughout their separation and never officially moved out of the L.A. home they shared.
Now, says the source, "They're trying to start again."
With reporting by AILI NAHAS