The siblings arrived in Edinburgh with their mother Lesya just over a year ago, and has planned to return to Ukraine to visit their father Koli in the summer. But he was killed two days before their return.
They are among the more than 11,000 Ukrainian refugees who have settled or arrived safely in Edinburgh since February 2022.
Also present at the service was Hannah Beaton-Hawryluk, chair of the Association of Ukrainians in GB Edinburgh.
She said: “We have to remember. War is all over the world, all of the time. Our forefathers fought for our freedoms – we cannot forget that. If we fail to remember the mistakes of the past, we will never, ever learn.
“Lesya’s family are one of thousands that have experienced terminal heartbreak in the last 20 months. The loss of her beloved husband, and father to her children, Koli, brutally outlines why to fail to learn from historic mistakes creates nothing other than an unstable world full of horror, destruction and immense sadness.
“I know how proud Lesya is of Marichka and Sviastoslav, who today laid a wreath on behalf of all children of Ukraine who have lost a parent to this war. ”
The children laid poppy wreaths at the service at Edinburgh’s City Chambers on Sunday morning (November 12).
Wreaths were also laid at the Stone of Remembrance by the Lord Provost Robert Aldridge, First Minister Humza Yousaf, Presiding Officer Alison Johnstone, and Baroness Annabel Goldie.
Crowds gathered for the ceremony along Edinburgh’s Royal Mile, which included a two minutes silence and parade by veterans and military personnel from Edinburgh Castle.
Commemorations also took place across Scotland, including at George Square in Glasgow.
Read more: Scotland honours the fallen in Remembrance Sunday service, in pictures
CEO of Legion Scotland Dr Claire Armstrong said: “From the First World War to the most recent of conflicts, we must always remember those who served.
“Many people have made the ultimate sacrifice in order to sustain our current way of life. Many more have made unthinkable sacrifices to maintain our freedoms. To them, and for them, we must say thank you, and we must remember them.
“As we recognise the extraordinary sacrifices of our Armed Forces community, it is also a chance to express our hopes for a peaceful future.
“Lest we forget such sacrifice, and lest we hope for peace and prosperity on behalf of those that Serve.”