Vanessa Bryant is lashing back at her mother -- claiming Sofia Laine only filed a lawsuit against her to "extort a financial windfall from our family."
Laine sued Vanessa earlier this week -- claiming Kobe Bryant had promised to take care of her for the rest of her life ... but after Kobe died in January, Vanessa left her out in the cold.
In her suit, Laine claims she worked as a nanny for Kobe and Vanessa -- and was "forced" to work around the clock for 18 years without proper meal or rest breaks.