Yes, they are sharing a home. If they are actually roommates as well, meaning sharing a bedroom, then it’s even worse, and clearly they should try to switch roommates within the house.
Does it matter who owns the house? In this case, all of them are tenants with an equal stake in it. It IS their home for an entire school year, which is just beginning.
Wow, that’s a sexist stereotype.
Here’s the thing. Clearly OP is upset and feeling stress, that if left unresolved, could affect her grades and performance in her sport. It bothers her enough to ask for help. The roommate is going about her business, apparently with no worries.
These two people aren’t strangers, they lived together last year and both made the choice to live together again. OP says everything was fine until admittedly, her personal issues affected others. Seems like she is trying to move past that and make amends. I stick with my original advice. Perhaps OP needs to voice her feelings and attempt to ameliorate the situation, for her own peace of mind.
As has been said, it’s possible to not be friends but still act friendly and respectful towards those you live with. That is what OP should expect from the roommate, nothing more.