Doria was expected to stay in the UK to help her daughter during her first few weeks of motherhood, however was seen walking her dogs near her home in California on Tuesday.
Earlier this year it was reported that the Duke and Duchess of Sussex had included a 'mother-in-law suite' inside their newly refurbished home just for Doria.
"Doria plans to be around a lot when the baby arrives, and there are plans or her to have a dedicated space at their new home," a source told Vanity Fair.
"She wants to be on hand to help Meghan and Harry with the baby."
Though it seems her stay at Frogmore Cottage was short lived.
The end of Doria's visit comes as Meghan's best friend Jessica Mulroney arrives in the UK to visit the Duchess and meet baby Archie Harrison for the first time.
Jessica was spotted with her daughter Ivy earlier this week at Toronto's Pearson International Airport before boarding a flight to London.
Meghan Markle and Prince Harry 'undermining' William and Kate