Michelle Williams at her Oz premiere Feb. 13
02/28/2013 at 01:00 PM EST
From the outside, it seemed as though Michelle Williams couldn't get enough
of boyfriend Jason Segel
. In reality, the actress may not have seen him as forever material.
"She cares a great deal for Jason but is not ready to make a commitment," a source tells PEOPLE. "Maybe if they were together day-to-day, she would have more confidence in a future. But not at this time."
Dating for a year
, PEOPLE confirmed on Tuesday that the pair called it quits
, citing long distance as the primary reason.
"Jason never got rid of his place in L.A., and Michelle's life with [daughter] Matilda was and has always been in New York," a second source says. "While Jason made every effort to make them a priority in his life – and they were top priority – he still couldn't drop everything and leave his life and career in L.A."
The road to romance has not been an easy one for Williams, 32.
The actress's ex, Heath Ledger
, was found dead
of an accidental prescription drug overdose in 2008, less than a year after they split. Left to care for their daughter alone, Williams stayed out of the spotlight, but began dating
director Spike Jonze for about a year. Following their split, she didn't have a public romance again until Segel, 33, in 2012.
Reporting by JENNIFER GARCIA and LINDA MARX