You mean the test was an IgM test, correct? This type of test for herpes is not valid - disregard it; only and IgG type specific test is the proper test for herpes.
Herpes Simplex IMG? That isn't a tye of herpes. There is Herpes Simplex 1 which is usually on the lip also called oral herpes. Then there is Herpes Simplex 2 that is usually genital herpes. Although you can spread HSV 1 to someones genitals via oral sex and spread HSv 2 on the mouth the same way. Has your daughter had any symptoms on her mouth or genitals? Stress cannot cause you to develop herpes but it can possibly trigger an outbreak if you already have herpes.