Lindsay Lohan just arrived at her mom's house on Long Island -- this after Dina Lohan's arrest for an off-the-charts DWI -- and she was definitely lacking in the support department.
Lindsay showed up in a black Porsche with her sister, Ali and an unidentified guy -- flashing a ton of side-boob as she walked into the house.
Shortly after Linds showed up ... her old attorney Mark Heller walked out of Dina's pad, and announced he's representing her in the DWI.
Heller pointed out Dina is a first time DWI offender with no prior record (criminally, anyway) -- and as a result he felt she would be treated with "fairness." Translation: he's hoping for no jail time.
As we previously reported ... Dina was arrested Thursday night ... and cops say she had a BAC of 0.2 -- nearly 3 times the legal limit.
Dina's still laying low -- the only sign of her all day was in the doorway as she let a friend out. She looked ... hazy.