Given that is a close family member and seems to be a "hacker." I'd make sure you change all your passwords and begin using two factor authentication as well. Don't forget to change your wifi password.
Given she knows the family well, she will be in a prime position to guess simple passwords like kid's names, birthdays, pet names etc. She will also be well positioned to be able to sweet talk your acquaintances into giving up your new numbers.
Also, make sure you don't put your new phone numbers into social media services like Facebook.