Jan Shane said it makes her angry that the 70-year-old star met the woman weeks before her sister committed suicide, reported Daily Mirror.
"The more I think about it, the angrier it makes me. My sister deserves more respect," Jan Shane said.
"It hasn't even been three months since she died. I now believe that he was a bigger part of her troubles than we knew about," she added.
Shane has labelled her Jagger "grotesquely disrespectful" after learning he flew ballerina Melanie Hamrick, 27, to stay with him in Zurich, where on June 1 they were seen embracing on his hotel balcony.
It was reported that the 'Rolling Stones' legend met Hamrick backstage at a concert in Tokyo days before Scott, 49, hanged herself in her New York apartment on March 17.