The All Saints singer was left devastated after it emerged over the summer (13) that the former Oasis rocker had fathered a daughter with American entertainment writer Liza Ghorbani.
A lawsuit filed by Ghorbani in New York demanding child support triggered the breakdown of Gallagher's marriage to Appleton, the mother of his 12-year-old son Gene, but they were spotted together for the first time outside the family home in London on Thursday (26Dec13).
Appleton was seen beaming as Gallagher hugged their son, while she later gave him a welcoming kiss on the cheek as they spent several hours together.
Appleton later opened up about her tough year in a series of Twitter.com messages, although she insisted that her heartache had made her stronger.
She wrote, "2013 taught me 1) No matter how good you treat people there will always be people that are blind, take advantage of it and regret it when it's gone.
"2) You're gonna get talked about, left out, used, and even lied to but you have to decide who's worth the pain and who isn't.
"3) Even the people you care about the most can walk out of your life. 2013 taught me to be prepared for whatever life throws at you."