The news comes one week after the Duke and Duchess of Sussex announced that they'll step back as senior members of the royal family, work to become financially independent, and split their time between North America and the U.K.
"Biggest argument right now is over money and how things will work," the source said. "Meghan wants more flexibility to work again and the couple wants to be able to earn a living similar to when Harry was in the military. He felt great fulfillment in his military career."
The Sussexes would like to have a "model like the Clintons or Obamas," according to the source, where they can do "meaningful work while making a living." ET has learned that it could mean projects like the Obamas have with Netflix.
"They need to find a balance where they raise money for their new foundation and have money-making ventures to support themselves," the source explained.
Additionally, royal courtiers will need to calculate what percentage of their work is public and official expenditures versus what they intend to be private and they will need to pay for themselves.
"The couple will be issued a range of options to consider today. Also very much at the heart of the discussions is security costs which the British taxpayer cover for members of the royal family," the source said. "They will get criticized whatever they do. They will need to be very careful."
Following the "very constructive discussions," Queen Elizabeth released a statement revealing that she and her family are "entirely supportive" of Harry and Meghan.
"Harry and Meghan have made clear that they do not want to be reliant on public funds in their new lives," the statement read in part. "It has therefore been agreed that there will be a period of transition in which the Sussexes will spend time in Canada and the U.K."
Likewise, another source told ET that the couple "will retain their home in Frogmore and carry out duties in the U.K, but also spend the majority of their time in North America."
According to a different royal source, Meghan and Harry didn't reach their decision lightly, and in fact, spent their six-week break reflecting "on their future role" and spending "private time as a family."
"This has been brewing in some form since discussions took place about a possible posting to Africa. Canada and Australia were also in the mix," the source said. "It’s more recently that the couple made the decision that they wanted a progressive new role. The couple has been struggling and Harry wants to make sure Meghan is happy. His number one priority is his family. It has not been an easy decision and he has been wrestling with his commitment to his family versus his keen sense of duty."