Wendy Williams Attorney Says She Has Good & Bad Days ... Don't Let 'Breakfast Club' Talk Fool You

Wendy Williams has some good and some bad days ... but people shouldn't assume she's fine just because she calls into an interview show -- so says her lawyer.

We spoke with Roberta Kaplan, Wendy's attorney, who tells us ... Wendy's dealing with frontal lobe dementia -- a neurological disease with no cure.

Because of this, Roberta explains, a state court found her unable to make legal and financial decision on her own ... and, because of the degenerative nature of the disease, she will require care for the remainder of her life.

That said, Wendy doesn't have 365 bad days a year ... some days are good, and she has a lot of clarity -- which is why she sounded totally normal when she called into "The Breakfast Club" this morning.

ICYMI ... Wendy went on the show Thursday and vented about her life -- saying she felt she was in prison and straight-up calling her life "f***ed up."

Wendy mostly blasts Sabrina Morrissey -- her conservator -- during the call. Roberta Kaplan is only representing Wendy in her lawsuit against A&E for producing the documentary "Where Is Wendy Williams?"

Williams made several other claims too -- alleging she can't receive phone calls from loved ones, and her only consistent interactions with people are when "nursemaids" give her pills.

Wendy's niece, Alex, claims she's not actually impaired ... and, tells her fans to get #FreeWendy trending to help her aunt.

But, Roberta Kaplan says otherwise ... and, she's telling fans not to let Wendy's enthusiasm fool them. Due to a guardianship court order, Sabrina Morrissey is prohibited from commenting on this story.