Hi there.

Cant really help much i have never seen or had herpes. Acne is common in pregnancy not sure why your DW thinks its herpes but could it be a coldsore??? if your DW is concerned i'd suggest a visit to the GP.
A coldsore is a form of herpes. (Herpes Simplex virus)

I usually use Carmex on coldsores and as a lip balm(in the little yellow tub) not to sure if zovirex etc is safe. Maybe ring her ob and ask if she is worried.