how to cancel subscriptions from a deceased family member

I am very sorry for your loss. Your best option is to contact Apple Support:

Get a call from Apple support to help solve your problem  https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Apple ID Support https://support.apple.com/apple-id

Apple Support Twitter https://twitter.com/AppleSupport

Apple ID account security for country-specific and region-specific

help https://support.apple.com/en-us/HT204169

Get Support: We’re here to help https://getsupport.apple.com/. Go

through the options to find the best support option.

Apple may want to see a copy of the death certificate and a copy of the will.

How to request access to a deceased family member's Apple accounts - Apple Support.