He told Express.co.uk: "Wherever they have been together they always make time to meet with local organisations and charities that Harry either has an existing relationship with or they want to learn more about".
"She has quietly been working on potential projects, and sources say we'll be seeing one of those come to life very soon".
Chelsy and Harry dated for seven years before splitting in 2011, reportedly because Chelsy found the pressures of royal life too hard. She also reportedly failed to curtsey for Markle after greeting her at her lunchtime wedding reception, as is royal protocol - and instead gave her a big hug (via The Mirror).
"In the end, she went [to the wedding] and promised Harry she wouldn't try and gatecrash the party", they add.
Katy Perry said earlier this week that she should have had "one more fitting", but fashion designer and royal wedding guest Victoria Beckham only had praise for the new Duchess of Sussex, saying she "looked absolutely beautiful".
During the Royal Wedding broadcast, there was plenty of discussion on social media regarding Harry's decision to invite his former girlfriends to his wedding, with many labelling the move unusual.
Vanity Fair previously reported she even offered to make Markle, 36, a one-off piece of jewellery as a wedding gift - an offer that was "politely turned down".
Ms Cohen had appeared to be on the way out of the royal household after an extraordinary row between her boss, Prince Charles and Prince Andrew.
"It was so full-on: insane and scary and uncomfortable". She added, "She looks really appropriate in navy and I love the bell sleeves".
"William and Kate had such an wonderful time in the Seychelles, so that could be an option, and Zanzibar has been at the top of their wish list for some time now", Scobie said.