Caitlyn Jenner -- Car Crash Victim's Stepkids ... You Can't Judge Our -

Caitlyn Jenner is out of line when she says the stepchildren of the woman who was killed in that PCH car crash had no right to sue because they were not financially dependent on her ... so claim the stepkids.

The stepchildren of Kim Howe just filed legal docs, claiming they did rely on her financially, but it's all kind of sketchy. They don't describe the extent of the dependence nor do they specifically describe the relationship.

In the docs, all they say is "not only did they have a very real relationship with Ms. Howe during the 40 years that she was their stepmother, but that they relied upon her, at least to some extent, for some of the necessities of life."

The lawyer for the stepson says in legal docs, "Stepchildren can be just as much children to their parents."

The father of the 2 kids died in 2003. A very close friend of Kim's tells TMZ he spoke with the stepdaughter shortly after Kim died back in February and the woman said she hadn't seen Kim since 2003. The friend also says Kim never spoke about her stepkids to him.

Jenner has asked a judge to toss the lawsuit because there's no evidence of financial dependence. If she's successful, she can't be sued for wrongful death because the stepkids are Howe's only living relatives.