The obituary linked by T Rex is for Charlotte's maternal grandmother. Her mother is listed there as well but she divorced Charlotte's father and had remarried, so she no longer had the same last name as her daughter Charlotte.
Charlotte's mother died in 2011 (the husband listed there is her 2nd husband but both husbands had the same first name).
Her
mother's obituary lists Charlotte as a survivor and doesn't mention her being missing.
Her father died in 2018 and
his obituary lists Charlotte as preceding him in death with a note saying "whereabouts unknown".