Jolie and partner Brad Pitt were expected to co-host last month's fundraiser at the Beverly Hills Hotel with Aniston, but opted to visit the Film Independent Spirit Awards instead.
James Haven claimed that his sister withdrew from the event because she did not want her fellow actress to feel uncomfortable, saying: "Angie is an incredibly strong but also incredibly sensitive woman, and she would always be careful when another woman's feelings are concerned.
"She'd go out of her way to make sure there was no situation that would hurt another woman because of her, and I'm talking about a situation like one of Brad's ex-partners or his ex-wife."
Pitt and Aniston were married for five years before splitting in January 2005.
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