this sounds hilariously great actually! if memory serves correctly i think charli grew up in nyc and her parents were soooo unbelievably strict that it still affects her abilities to befriend others and grow lasting relationships (she genuinely doesn't understand how to "bond" well with others her age) so i could see her having some family that she lived with upon first moving to boston, it could easily be an aunt or great aunt who took care of her and she just feels compelled to check in on her often so they would have a place to chat with each other and everything like that! charli would probably appear suuuuper awkward at first but the more she saw jamie the more comfortable she would get.