I'm frustrated with my roommate. she has a severe peanut all

I'm frustrated with my roommate. she has a severe peanut allergy and I have a severe tree nut allergy so our home is supposed to be nut free. But she brings home tree nuts all the time. I've asked her not to but she doesnt listen. I went to eat something today and apparently it was made with almond flour so I had a pretty severe reaction. I dont understand why she would do that if I dont do that to her.

just make it super clear.
send a text message about it. email about it. write it on the post it and attach on the board/refrigerator.
and also tell her (when she is in mood to listen) what you go through (severe reaction)-describe that.
don't blame her for what she did. don't criticize her. don't see it as a fairness issue.... so that she doesn't take it personally/get emotional/bitter.
gently remind her (we all forget sometimes)
and then if this continues, at that time, make some decision (as to what will you do if this happens again. which measure will you take) and then let her know/warn her. then, if that happens again, take action accordingly.