Christie Brinkley is publicly battling her brother while tweeting barbs towards ex-husband Billy Joel's new wife (his fourth). Since the death of their parents, Christie and brother Gregory Donal Brinkley have been at odds over memorial services and the handling of the estate.

As reported earlier in the Inquisitr, even Christie Brinkley's daughter, Sailor, has joined in, tweeting venom towards her uncle.

"Just know not to trust a man who tries to ruin and create conflict on his 17 year old niece's birthday … I don't trust him nor do i trust what he does or what he believes in. I in no way want to be connected to him or his lifestyle," Sailor wrote on Twitter.

Donald Brinkley planned a service for their late parents, which Christie Brinkley allegedly blew off in favor of her own service. In what now it seems is the Brinkley way, Donald Brinkley also took to social media to express his displeasure.

"It is heart wrenching to watch Christie Brinkley [descend] into this CHARACTER ASSASSINATION," Gregory Donald wrote on his Facebook page, adding that he thought he and his sister "had developed a relationship that was strong and true."

"I had even left my work to spend extra time with mom and dad and also to take care of Christie's children while she danced and sang on the stage of Chicago the Musical."

The root of the conflict seems to be money, and the way their father's (step-father's, technically) end-of-life requests were or were not carried out.Meanwhile, there seems to be some debate over the way Christie Brinkley has expressed her "well wishes" towards Billy Joel's new bride. Some think her tweet that read "Congratulation to the glowing bride and groom. And to my daughter Alexa, who has a wonderful friend in Alexis! Wishing the growing family every happiness!" was a sincere bon mot, while others see it as a snide comment.

Alexa Ray Joel, Christie Brinkley's daughter with piano man Billy Joel, is just four years younger than her new stepmother, which is perhaps why Christie used the word "friend" in her tweet. Also, the mention of "growing family" insinuates that the fourth bride of Billy Joel is, indeed, pregnant.

Regardless of intent, Christie Brinkley seems to have an all-out social media battle on her hands!

Do you think Christie Brinkley was wishing the happy couple well, or throwing shade?

[Photos courtesy of Daily Mail and Huffington Post]