It would be helpful if she did, of course (assuming she was partly at fault for what happened). Even if she only said she was sorry that things got out of hand, it still could help heal the break between you.
But what if she doesn’t apologize? Will you go on refusing to talk to each other the rest of your lives? I certainly hope not. After all, she may not feel she has any reason to apologize — and even if you think she’s wrong, the break between you will continue if nothing changes. In addition, her pride may be getting in the way; she may find it hard to admit she was wrong.
Whatever the reason, ask God to help you put the past behind you, and take whatever steps you can to let her know you care about her and want to have a good relationship. Don’t bring up what happened in the past; it will only reopen old wounds. The Bible wisely says, “A man’s wisdom gives him patience; it is to his glory to overlook an offense” (Proverbs 19:11).
In addition, ask God to help you guard your tongue so you’ll avoid problems like this in the future. Almost nothing gets us in trouble quicker than an undisciplined tongue — but almost nothing brings healing quicker than a tongue guided by wisdom and love. The Bible says, “Reckless words pierce like a sword, but the tongue of the wise brings healing” (Proverbs 12:18).