My friend's mom kind of hates me right now. . .?

Question

My friend and I got into the biggest argument ever last night. She ended up punching out a window. (She is an emotionally unstable person. . .she's been under a lot of stress lately.)

It taught me a huge lesson. From now on I've sworn to stop every future argument from happening. I have been taking advice and looking up techniques. Already I have tested it and I know I will get better.

Only problem is that her mom doesn't want her to TALK to me. My friend has called me a few times when her mom is gone. She says maybe when her mom is cooled off she will let us talk, but not often. It upsets me because I wrote her mom a sincere apology letter and she refuses to read it. If she read it, she would know I do no plan on making any problems in the future and that I care about her daughter.

What should I do? Should I just wait and see how long until she cools off? I'm beginning to think that she hates me and I don't know what to do with myself. I miss talking to my friend and I want her mom to read my note.