Michelle and Thomas were seen buying baby clothes at Seraphine's maternity boutique in Kensington, in preparation for the arrival of their first child together.
Meanwhile, Michelle has previously spoken candidly about her search for love following Ledger's death in 2008.
The Hollywood star admitted she always remained optimistic that she would one day find someone who could fill the void in her life.
Speaking in 2018, she shared: "I never gave up on love.
"I always say to Matilda, 'Your dad loved me before anybody thought I was talented, or pretty, or had nice clothes.'"
Michelle has made a concerted effort to keep her personal life away from the spotlight.
But, on the other hand, she recognises that talking about her own issues could help other people to deal with their problems.
She said: "I don't really want to talk about any of it. But what if this helps somebody?
"What if somebody who has always journeyed in this way, who has struggled as much as I struggled, and looked as much as I looked, finds something that helps them?
"Don't settle. Don't settle for something that feels like a prison or is hard, or hurts you. If it doesn't feel like love, it's not love."
