The presenter commented on a recent fashion snap on Ruth's Instagram page with a sweet compliment, writing: "What a beauty," alongside a heart emoji.
Ruth's own post showed her posing in a patterned jumper from her QVC range, which she captioned: "If you were trying to get hold of this jumper last week but missed out. Just to let you know there are a few sizes available again in navy... be quick! Click the link in my bio."
Alison sweetly commented on Ruth's Instagram
It comes as rumours continue to circulate that Ruth and her husband and co-presenter, Eamonn Holmes, are being replaced by Alison and Dermot O'Leary.
WATCH: Ruth and Alison reunite on This Morning
None of the show's presenters have yet confirmed or denied the reports, which would see Ruth and Eamonn continue to front This Morning over the summer but be replaced by Alison and Dermot on Fridays during the rest of the year.
Alison and Ruth also appeared together on the show on Wednesday, briefly coming together via video link as This Morning handed over to Loose Women for a short segment.
Ruth and Eamonn are thought to be leaving their Friday hosting roles
Ruth also gave some telling comments to The Mirror Notebook recently, before it was suggested that the couple were set to be axed from the show.
She said of their hard work over the years: "We put the work in. We didn't do a reality show and get an overnight job on telly. We've come through the ranks."
She added: "Eamonn was only 19 when he started out. And he was doing the teatime news in Belfast during The Troubles. It was heavy stuff. And he's now got an OBE for services to broadcasting."