Us Weekly reported at the time that the rumours "turned out to be a good thing for them in the end."
A family friend of the Middletons divulged to the outlet, "Kate finds the rumours hurtful, obviously, and hates the thought that one day her children will be able to read about them online."
"It forced her and William to sit back and examine their relationship, which they realised they should have been doing more often."
Another sourced noted that the initial rumours "didn't go down well" with the Duchess, but that their marriage remains strong.
"[They] are doing a great job at getting their marriage back on track again," that source said. "It's not unusual to have a few hiccups in a marriage, especially after eight years, and Kate and William are no different. They're still going strong. Regardless of their ups and downs, they love each other dearly and their kids are the most important thing in their lives."