Grace Elinor Robotti, 65, is charged with the second degree murder of Louie, who was her daughter-in-law and mother to a three-year-old boy.
Robotti's brother, Pier Louis Robotti, 61, is charged with interfering with human remains and being an accessory after the fact by allegedly helping his sister escape.
"She'd gone to Penticton because she had family and friends here and was due to fly back [to Vancouver] on the fourth but never made that plane," said Penticton RCMP Sgt. Rick Dellebuur.
"And family became worried because they couldn't reach her so that is how we have become involved."
Grace Robotti and Pier Robotti both made a brief court appearance on Monday morning.
They're scheduled to be back in court on Thursday.
RCMP say Louie's body has been recovered, but no other circumstances about her death have been released.
Louie was originally from Oliver and had moved to Vancouver last year.