 In 1987 , she was criticised when it emerged that two of her nieces , Katherine Bowes @-@ Lyon and Nerissa Bowes @-@ Lyon , had both been committed to a psychiatric hospital because they were severely handicapped . However , Burke 's Peerage had listed the sisters as dead , apparently because their mother , Fenella ( the Queen Mother 's sister @-@ in @-@ law ) , " was ' extremely vague ' when it came to filling in forms and might not have completed the paperwork for the family entry correctly " . When Nerissa had died the year before , her grave was originally marked with a plastic tag and a serial number . The Queen Mother claimed that the news of their institutionalisation came as a surprise to her . 
