The fiercely private music icon was admitted to hospital following the health scare, and she has been recuperating ever since - but details about her health have been scarce.
On Wednesday (14Oct15), Collins took to Facebook to offer up an update on Mitchell, and shared her high hopes for a full recovery.
"I have just heard from a close mutual friend that Joni is walking, talking, painting some, doing much rehab every day, and making good progress," Collins wrote.
"I have another friend who went through something similar - it does take a long time, three years for my friend, who has really totally recovered professionally and personally. I will try my best to see our songbird (Mitchell) when I am in LA in the coming weeks."
Collins' post was later shared on Mitchell's official website.
The two singer/songwriters have been linked for more than 50 years after Collins recorded Mitchell's classic Both Sides Now in 1967.