A Canadian woman accused in England of killing her two children made a court appearance in London on Saturday and was formally charged with murder.

Jewelry designer Felicia Boots was remanded into custody until Tuesday. She is alleged to have killed her 14-month-old daughter, Lily, and 10-week-old son, Mason.

British media reports say Boots "spoke softly in her Canadian accent" in court, not saying much other than to confirm her name and address. As she left the court she waved to her parents, who were in the visitors' gallery, as well as a friend.

Jeffrey and Felicia Boots, originally from Canada, moved into their five-bedroom house in London two weeks ago after the birth of their second child, reports say. (Facebook)

Boots, 34, is originally from the Toronto area. She moved to London a few years ago with her Canadian husband, Jeff Boots, a former investment banker with Bank of Montreal.

Their home in Wandsworth, South London, is located in an area known to many as "nappy valley" for the number of young families living there.

People in the upscale neighbourhood say they saw the husband come home early Wednesday evening and moments later he called out for help.

Autopsies have not yielded results regarding the cause of death.