Casey Kasem's Wife Jean -- I Still Do His Toenails

Casey Kasem's wife Jean insists she's taking great care of her ailing hubby, right down to giving him manicures and pedicures.

Jean has just filed legal docs through her lawyer, Marshall Grossman, -- docs obtained by TMZ -- challenging the attempt by Casey's 3 kids from a prior marriage to win a conservatorship. The kids say Jean has not allowed them to see their dad -- who has advanced Parkinson's and early onset of dementia -- for months and they fear he's not being properly cared for.

Jean says the kids are ingrates who have sponged off their dad for years. Jean says she and Casey have loaned the kids approx $100k-$150k PER YEAR over many years to pay for their school, housing, cars, parking tickets, travel and other stuff. Jean also says she sent Julie $50k back in July, 2000 and it was never repaid, and that's just one example.

Jean says if there's a need for a conservator, it should be her. Casey's kids say they have a power of attorney from 2007 that gives them control over his health care, but Jean says that document was nullified by a subsequent health care directive in 2011 giving her control.