She should get a notice of adverse action explaining why she was denied. If this is not given, tell her to request it because by law it should be provided. She will know for sure why she was denied.
They should notify her for sure. If she does not hear back, apply again but be sure that it won't be hurting her score. I know some applications for specific loans can actually hurt when you get rejected.
You will get notified and it may or may not drop your credit score. It depends on the loan agency or bank that declined you. Have to be careful not to keep applying if it is lowering your score.
In most cases, you get notified by mail, e-mail, or phone call. Sometimes all three. They will state you have been rejected and give you an outline as to why. Some personal loans come with a cost even if you get rejected in the form of hurting your credit score, as mentioned.
I think everything was covered already but I just wanted to add that when I was rejected, I waited a month and was able to get the personal loan from the very place that declined me. This came down to raising my scores over 700. I was able to go from 689 to 703 and they accepted it.