HIV is transmitted in very well known, clear ways. It's only transmitted from having unprotected vaginal or anal sex or sharing IV drug needles. She uses a condom usually as most sex workers do to protect themselves. You had condom sex, that is not a risk. However, a condom breaking is. So, you will need to test. She sounds like a known person to you and doesn't have any reason to lie. And you know her husband? I'd test with a 4th generation DUO at 28 days to be sure and as anxious says, stay busy until that time to ward off anxiety.
If she always uses a condom that isn't broken then she will not be positive. She said she is negative, so it is up to you to figure whether or not to trust your friend that she had no other unprotected vaginal after her last test window. If you don't want to trust your friend's word, you need to test with a duo after 4 weeks or any other test after 12 for a conclusive result. Ask her when she tested last because if it was recent, that will help cut your anxiety while you wait for your test.