The blonde beauty also posted a smiling snapshot with her estranged husband, 40.
The former couple, who got married in the South of France in July 2013, first sparked rumours they were on the verge of splitting last September after Chad skipped Avril's 30th birthday party in Las Vegas.
An insider claimed at the time: "It's over. He has been going around LA telling people that they are divorcing."
But Kroeger later claimed he was relieved when Lavigne, who split from Sum 41 rocker Deryck Whibley in 2010 after four years of marriage, finally confirmed she was secretly battling Lyme disease following months of speculation about their marriage.
Speaking in April, he said: "I'm like, 'Okay, the wife has come out and said this, and now I don't have to keep hiding.'
"With everyone going 'What's wrong with your wife? What's wrong with your wife?' and me just going, 'Ah, she's gonna be fine.'
"I'm like 'Okay, I can talk about this now.' Things are looking up and definitely getting better."
- Bang! Showbiz